diff --git a/.rubocop_todo/rspec/change_by_zero.yml b/.rubocop_todo/rspec/change_by_zero.yml
index 74acf4d504e9f04cf3fe5ecb513fc2c67a0e3522..c88bc67c044902a24e1119d865c98caeed7414aa 100644
--- a/.rubocop_todo/rspec/change_by_zero.yml
+++ b/.rubocop_todo/rspec/change_by_zero.yml
@@ -117,7 +117,6 @@ RSpec/ChangeByZero:
     - 'spec/workers/gitlab/bitbucket_import/stage/import_pull_requests_worker_spec.rb'
     - 'spec/workers/gitlab/bitbucket_server_import/stage/import_pull_requests_worker_spec.rb'
     - 'spec/workers/gitlab/bitbucket_server_import/stage/import_repository_worker_spec.rb'
-    - 'spec/workers/gitlab/bitbucket_server_import/stage/import_users_worker_spec.rb'
     - 'spec/workers/packages/cleanup_package_file_worker_spec.rb'
     - 'spec/workers/packages/maven/metadata/sync_worker_spec.rb'
     - 'spec/workers/packages/rubygems/extraction_worker_spec.rb'
diff --git a/app/workers/gitlab/bitbucket_server_import/stage/import_repository_worker.rb b/app/workers/gitlab/bitbucket_server_import/stage/import_repository_worker.rb
index 573c73cd7dfe66275ff118797ac211c68fbfda43..b378d07d59cd6040a7c68a0c69079522ed02dd2e 100644
--- a/app/workers/gitlab/bitbucket_server_import/stage/import_repository_worker.rb
+++ b/app/workers/gitlab/bitbucket_server_import/stage/import_repository_worker.rb
@@ -14,11 +14,7 @@ def import(project)
 
           importer.execute
 
-          if Feature.enabled?(:bitbucket_server_convert_mentions_to_users, project.creator)
-            ImportUsersWorker.perform_async(project.id)
-          else
-            ImportPullRequestsWorker.perform_async(project.id)
-          end
+          ImportPullRequestsWorker.perform_async(project.id)
         end
 
         def importer_class
diff --git a/app/workers/gitlab/bitbucket_server_import/stage/import_users_worker.rb b/app/workers/gitlab/bitbucket_server_import/stage/import_users_worker.rb
index 4c323a117556870818d9c393d9a60c94c15dd43b..7d2602283e3c9d59271b2ea1bbbae23f93b8feed 100644
--- a/app/workers/gitlab/bitbucket_server_import/stage/import_users_worker.rb
+++ b/app/workers/gitlab/bitbucket_server_import/stage/import_users_worker.rb
@@ -10,13 +10,7 @@ class ImportUsersWorker
 
         private
 
-        def import(project)
-          importer = importer_class.new(project)
-
-          importer.execute
-
-          ImportPullRequestsWorker.perform_async(project.id)
-        end
+        def import(project); end
 
         def importer_class
           Importers::UsersImporter
diff --git a/config/feature_flags/development/bitbucket_server_convert_mentions_to_users.yml b/config/feature_flags/development/bitbucket_server_convert_mentions_to_users.yml
deleted file mode 100644
index 90ea8d56c0acca704cb4ef12d497d529b46d05b7..0000000000000000000000000000000000000000
--- a/config/feature_flags/development/bitbucket_server_convert_mentions_to_users.yml
+++ /dev/null
@@ -1,8 +0,0 @@
----
-name: bitbucket_server_convert_mentions_to_users
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/139097
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/434453
-milestone: '16.7'
-type: development
-group: group::import and integrate
-default_enabled: false
diff --git a/lib/gitlab/bitbucket_server_import/importers/pull_request_importer.rb b/lib/gitlab/bitbucket_server_import/importers/pull_request_importer.rb
index 9712a8d25514623f85e3789322b21d8495276231..7e2aba7b61645ebcb6152126ce72ab32dc2dde8d 100644
--- a/lib/gitlab/bitbucket_server_import/importers/pull_request_importer.rb
+++ b/lib/gitlab/bitbucket_server_import/importers/pull_request_importer.rb
@@ -5,14 +5,13 @@ module BitbucketServerImport
     module Importers
       class PullRequestImporter
         include Loggable
+        include Gitlab::Import::UsernameMentionRewriter
         include ::Import::PlaceholderReferences::Pusher
 
         def initialize(project, hash)
           @project = project
           @formatter = Gitlab::ImportFormatter.new
           @user_finder = UserFinder.new(project)
-          @mentions_converter = Gitlab::Import::MentionsConverter.new('bitbucket_server', project)
-
           # Object should behave as a object so we can remove object.is_a?(Hash) check
           # This will be fixed in https://gitlab.com/gitlab-org/gitlab/-/issues/412328
           @object = hash.with_indifferent_access
@@ -55,21 +54,14 @@ def execute
 
         private
 
-        attr_reader :object, :project, :formatter, :user_finder, :mentions_converter
+        attr_reader :object, :project, :formatter, :user_finder
 
         def description
           description = ''
           description += author_line
           description += object[:description] if object[:description]
 
-          description = mentions_converter.convert(description) if convert_mentions?
-
-          description
-        end
-
-        def convert_mentions?
-          Feature.enabled?(:bitbucket_server_convert_mentions_to_users, project.creator) &&
-            !user_mapping_enabled?(project)
+          wrap_mentions_in_backticks(description)
         end
 
         def author_line
diff --git a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_importer.rb b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_importer.rb
index fc9f1d81b9bf3ff59689ba9976f5deeb2672e0fc..0d7c00569656b4ae49275dd1100f00c8a336ace0 100644
--- a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_importer.rb
+++ b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_importer.rb
@@ -7,6 +7,7 @@ module PullRequestNotes
         # Base class for importing pull request notes during project import from Bitbucket Server
         class BaseImporter
           include Loggable
+          include ::Gitlab::Import::UsernameMentionRewriter
           include ::Import::PlaceholderReferences::Pusher
 
           # @param project [Project]
@@ -15,7 +16,6 @@ def initialize(project, merge_request)
             @project = project
             @user_finder = UserFinder.new(project)
             @formatter = Gitlab::ImportFormatter.new
-            @mentions_converter = Gitlab::Import::MentionsConverter.new('bitbucket_server', project)
             @merge_request = merge_request
           end
 
@@ -25,7 +25,7 @@ def execute(_args)
 
           private
 
-          attr_reader :project, :user_finder, :merge_request, :mentions_converter
+          attr_reader :project, :user_finder, :merge_request
         end
       end
     end
diff --git a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_note_diff_importer.rb b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_note_diff_importer.rb
index 0e73959882f2247b2c6fa79a7621af12710ecf6b..1cffe9f8998dc149be58925b1c618d6e3331224e 100644
--- a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_note_diff_importer.rb
+++ b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/base_note_diff_importer.rb
@@ -62,19 +62,19 @@ def pull_request_comment_attributes(comment)
               note = "*By #{comment[:author_username]} (#{comment[:author_email]})*\n\n"
             end
 
-            comment_note = mentions_converter.convert(comment[:note])
-
             note +=
               # Provide some context for replying
               if comment[:parent_comment_note]
-                "> #{comment[:parent_comment_note].truncate(PARENT_COMMENT_CONTEXT_LENGTH)}\n\n#{comment_note}"
+                parent_comment_note = comment[:parent_comment_note].truncate(80, omission: ' ...')
+
+                "> #{parent_comment_note}\n\n#{comment[:note]}"
               else
-                comment_note
+                comment[:note]
               end
 
             {
               project: project,
-              note: note,
+              note: wrap_mentions_in_backticks(note),
               author_id: author,
               created_at: comment[:created_at],
               updated_at: comment[:updated_at]
@@ -98,7 +98,7 @@ def create_basic_fallback_note(merge_request, comment, position)
 
             note_text += " #{position.old_path}:#{position.old_line} -->" if position.old_line
             note_text += " #{position.new_path}:#{position.new_line}" if position.new_line
-            note_text += "*\n\n#{comment[:note]}"
+            note_text += "*\n\n#{wrap_mentions_in_backticks(comment[:note])}"
 
             attributes[:note] = note_text
 
diff --git a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer.rb b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer.rb
index 89f46c98fd139d1abb1268ee8dd3c9ab15432a50..7f470e17f8d8837d80722ed4400e33540c7efdc3 100644
--- a/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer.rb
+++ b/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer.rb
@@ -5,6 +5,7 @@ module BitbucketServerImport
     module Importers
       class PullRequestNotesImporter
         include ::Gitlab::Import::MergeRequestHelpers
+        include ::Gitlab::Import::UsernameMentionRewriter
         include Loggable
         include ::Import::PlaceholderReferences::Pusher
 
@@ -12,7 +13,6 @@ def initialize(project, hash)
           @project = project
           @user_finder = UserFinder.new(project)
           @formatter = Gitlab::ImportFormatter.new
-          @mentions_converter = Gitlab::Import::MentionsConverter.new('bitbucket_server', project)
           @object = hash.with_indifferent_access
         end
 
@@ -30,7 +30,7 @@ def execute
 
         private
 
-        attr_reader :object, :project, :formatter, :user_finder, :mentions_converter
+        attr_reader :object, :project, :formatter, :user_finder
 
         def import_notes_in_batch(merge_request)
           activities = client.activities(project_key, repository_slug, merge_request.iid)
@@ -221,23 +221,21 @@ def pull_request_comment_attributes(comment)
             note = "*By #{comment.author_username} (#{comment.author_email})*\n\n"
           end
 
-          comment_note = if convert_mentions?
-                           mentions_converter.convert(comment.note)
-                         else
-                           comment.note
-                         end
+          comment_note = comment.note
 
           note +=
             # Provide some context for replying
             if comment.parent_comment
-              "> #{comment.parent_comment.note.truncate(80)}\n\n#{comment_note}"
+              parent_comment_note = comment.parent_comment.note.truncate(80, omission: ' ...')
+
+              "> #{parent_comment_note}\n\n#{comment_note}"
             else
               comment_note
             end
 
           {
             project: project,
-            note: note,
+            note: wrap_mentions_in_backticks(note),
             author_id: author,
             created_at: comment.created_at,
             updated_at: comment.updated_at,
@@ -245,11 +243,6 @@ def pull_request_comment_attributes(comment)
           }
         end
 
-        def convert_mentions?
-          Feature.enabled?(:bitbucket_server_convert_mentions_to_users, project.creator) &&
-            !user_mapping_enabled?(project)
-        end
-
         def author(comment)
           if user_mapping_enabled?(project)
             user_finder.uid(
diff --git a/lib/gitlab/bitbucket_server_import/importers/users_importer.rb b/lib/gitlab/bitbucket_server_import/importers/users_importer.rb
deleted file mode 100644
index 588c7be5dd4bd6db7030030607f28d7b39d275c6..0000000000000000000000000000000000000000
--- a/lib/gitlab/bitbucket_server_import/importers/users_importer.rb
+++ /dev/null
@@ -1,70 +0,0 @@
-# frozen_string_literal: true
-
-module Gitlab
-  module BitbucketServerImport
-    module Importers
-      class UsersImporter
-        include Loggable
-        include Gitlab::Import::UserFromMention
-
-        BATCH_SIZE = 100
-
-        def initialize(project)
-          @project = project
-          @project_id = project.id
-        end
-
-        attr_reader :project, :project_id
-
-        def execute
-          log_info(import_stage: 'import_users', message: 'starting')
-
-          current = page_counter.current
-
-          loop do
-            log_info(
-              import_stage: 'import_users',
-              message: "importing page #{current} using batch size #{BATCH_SIZE}"
-            )
-
-            users = client.users(project_key, page_offset: current, limit: BATCH_SIZE).to_a
-
-            break if users.empty?
-
-            cache_users(users)
-
-            current += 1
-            page_counter.set(current)
-          end
-
-          page_counter.expire!
-
-          log_info(import_stage: 'import_users', message: 'finished')
-        end
-
-        private
-
-        def cache_users(users)
-          users_hash = users.each_with_object({}) do |user, hash|
-            cache_key = source_user_cache_key('bitbucket_server', project_id, user.username)
-            hash[cache_key] = source_user_cache_value(user.email, type: :email)
-          end
-
-          cache_multiple(users_hash)
-        end
-
-        def client
-          @client ||= BitbucketServer::Client.new(project.import_data.credentials)
-        end
-
-        def project_key
-          project.import_data.data['project_key']
-        end
-
-        def page_counter
-          @page_counter ||= Gitlab::Import::PageCounter.new(project, :users, 'bitbucket-server-importer')
-        end
-      end
-    end
-  end
-end
diff --git a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_importer_spec.rb b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_importer_spec.rb
index 67f2925cde3330013635cff9596af23dd7ba24dc..e4ad27086df21ab1da54f1cc7af36ceab1ee7d1b 100644
--- a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_importer_spec.rb
+++ b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_importer_spec.rb
@@ -53,6 +53,26 @@
       )
     end
 
+    describe 'when handling @ username mentions' do
+      let(:original_body) { "I said to @sam_allen.greg the code should follow @bob's advice. @.ali-ce/group#9?" }
+      let(:expected_body) do
+        "I said to `@sam_allen.greg` the code should follow `@bob`'s advice. `@.ali-ce/group#9`?"
+      end
+
+      let(:pull_request_data) do
+        Gitlab::Json.parse(fixture_file('importers/bitbucket_server/pull_request.json'))
+        .merge({ "description" => original_body })
+      end
+
+      it 'inserts backticks around mentions' do
+        importer.execute
+
+        merge_request = project.merge_requests.find_by_iid(pull_request.iid)
+
+        expect(merge_request.description).to eq(expected_body)
+      end
+    end
+
     describe 'refs/merge-requests/:iid/head creation' do
       before do
         project.repository.create_branch(pull_request.source_branch_name, 'master')
@@ -164,22 +184,9 @@
         )
       end
 
-      context 'when the `bitbucket_server_convert_mentions_to_users` flag is disabled' do
-        before do
-          stub_feature_flags(bitbucket_server_convert_mentions_to_users: false)
-        end
-
-        it 'does not convert mentions' do
-          expect_next(Gitlab::Import::MentionsConverter, 'bitbucket_server', project).not_to receive(:convert)
-
-          importer.execute
-        end
-      end
-
       context 'when alternate UCM flags are disabled' do
         before do
           stub_feature_flags(
-            bitbucket_server_convert_mentions_to_users: false,
             bitbucket_server_user_mapping: false
           )
         end
diff --git a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/inline_spec.rb b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/inline_spec.rb
index 467dcc52f86bad5323df7f0ebd8d18a6d98cb3f8..89a2b045682c27bb7826c23bb3aeb9909e6cc13b 100644
--- a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/inline_spec.rb
+++ b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/inline_spec.rb
@@ -11,7 +11,6 @@
 
   let_it_be(:merge_request) { create(:merge_request, source_project: project) }
   let_it_be(:now) { Time.now.utc.change(usec: 0) }
-  let_it_be(:mentions_converter) { Gitlab::Import::MentionsConverter.new('bitbucket_server', project) }
   let_it_be(:reply) do
     {
       author_email: 'reply_author@example.org',
@@ -45,10 +44,6 @@
   let_it_be(:reply_source_user) { generate_source_user(project, reply[:author_username]) }
   let_it_be(:note_source_user) { generate_source_user(project, pr_inline_comment[:author_username]) }
 
-  before do
-    allow(Gitlab::Import::MentionsConverter).to receive(:new).and_return(mentions_converter)
-  end
-
   def expect_log(stage:, message:, iid:, comment_id:)
     allow(Gitlab::BitbucketServerImport::Logger).to receive(:info).and_call_original
     expect(Gitlab::BitbucketServerImport::Logger)
@@ -69,8 +64,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
     end
 
     it 'imports the threaded discussion' do
-      expect(mentions_converter).to receive(:convert).and_call_original.twice
-
       expect { importer.execute(pr_inline_comment) }.to change { Note.count }.by(2)
 
       expect(merge_request.discussions.count).to eq(1)
@@ -101,6 +94,51 @@ def expect_log(stage:, message:, iid:, comment_id:)
       importer.execute(pr_inline_comment)
     end
 
+    context 'when note has @ username mentions' do
+      let(:original_text) { "Attention: @ali has worked on this. @fred's work from @.ali-ce/group#9?" }
+      let(:expected_text) { "Attention: `@ali` has worked on this. `@fred`'s work from `@.ali-ce/group#9`?" }
+      let(:mention_reply) do
+        {
+          author_email: 'reply_author@example.org',
+          author_username: 'reply_author',
+          note: original_text,
+          created_at: now,
+          updated_at: now,
+          parent_comment_note: nil
+        }
+      end
+
+      let(:mention_comment) do
+        {
+          id: 7,
+          file_type: 'ADDED',
+          from_sha: 'c5f4288162e2e6218180779c7f6ac1735bb56eab',
+          to_sha: 'a4c2164330f2549f67c13f36a93884cf66e976be',
+          file_path: '.gitmodules',
+          old_pos: nil,
+          new_pos: 4,
+          note: original_text,
+          author_email: 'inline_note_author@example.org',
+          author_username: 'inline_note_author',
+          comments: [mention_reply],
+          created_at: now,
+          updated_at: now,
+          parent_comment_note: nil
+        }
+      end
+
+      it 'inserts backticks around the mentions' do
+        importer.execute(mention_comment)
+
+        notes = merge_request.notes.order(:id).to_a
+        start_note = notes.first
+        expect(start_note.note).to end_with(expected_text)
+
+        reply_note = notes.last
+        expect(reply_note.note).to eq(expected_text)
+      end
+    end
+
     context 'when note is invalid' do
       let(:invalid_comment) do
         pr_inline_comment.merge(
@@ -111,8 +149,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
 
       it 'fallback to basic note' do
-        expect(mentions_converter).to receive(:convert).and_call_original.twice
-
         expect { importer.execute(invalid_comment) }.to change { Note.count }.by(1)
 
         expect(merge_request.discussions.count).to eq(1)
@@ -125,7 +161,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
 
       it 'logs its fallback' do
-        expect(mentions_converter).to receive(:convert).and_call_original.twice
         expect_log(
           stage: 'create_diff_note',
           message: 'creating standalone fallback for DiffNote',
@@ -148,8 +183,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
 
       it 'imports the threaded discussion' do
-        expect(mentions_converter).to receive(:convert).and_call_original.twice
-
         expect { importer.execute(pr_inline_comment) }.to change { Note.count }.by(2)
 
         expect(merge_request.discussions.count).to eq(1)
@@ -162,16 +195,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
         expect(reply_note.author_id).to eq(reply_author.id)
       end
 
-      context 'when converting mention is failed' do
-        it 'logs its exception' do
-          expect(mentions_converter).to receive(:convert).and_raise(StandardError)
-          expect(Gitlab::ErrorTracking).to receive(:log_exception)
-            .with(StandardError, include(import_stage: 'create_diff_note'))
-
-          importer.execute(pr_inline_comment)
-        end
-      end
-
       it 'does not push placeholder references' do
         importer.execute(pr_inline_comment)
 
diff --git a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/standalone_notes_spec.rb b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/standalone_notes_spec.rb
index 01fd4843f038863d6f189a3b0185ffa6ff717860..57421fab9abcd1a5c5f8fe0da3dd191eeb1fd9e1 100644
--- a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/standalone_notes_spec.rb
+++ b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes/standalone_notes_spec.rb
@@ -8,7 +8,6 @@
   let_it_be(:project) { create(:project, :repository, :bitbucket_server_import, :import_user_mapping_enabled) }
   let_it_be(:merge_request) { create(:merge_request, source_project: project) }
   let_it_be(:now) { Time.now.utc.change(usec: 0) }
-  let_it_be(:mentions_converter) { Gitlab::Import::MentionsConverter.new('bitbucket_server', project) }
   let_it_be(:author_details) do
     {
       author_name: 'John Notes',
@@ -30,10 +29,6 @@
 
   let_it_be(:source_user) { generate_source_user(project, pr_comment[:author_username]) }
 
-  before do
-    allow(Gitlab::Import::MentionsConverter).to receive(:new).and_return(mentions_converter)
-  end
-
   def expect_log(stage:, message:, iid:, comment_id:)
     allow(Gitlab::BitbucketServerImport::Logger).to receive(:info).and_call_original
     expect(Gitlab::BitbucketServerImport::Logger)
@@ -53,8 +48,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
     end
 
     it 'imports the stand alone comments' do
-      expect(mentions_converter).to receive(:convert).and_call_original
-
       expect { importer.execute(pr_comment) }.to change { Note.count }.by(1)
 
       expect(merge_request.notes.count).to eq(1)
@@ -93,8 +86,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
 
       it 'imports multiple comments' do
-        expect(mentions_converter).to receive(:convert).and_call_original.twice
-
         expect { importer.execute(pr_comment) }.to change { Note.count }.by(2)
 
         expect(merge_request.notes.count).to eq(2)
@@ -115,6 +106,41 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
     end
 
+    context 'when note has @ username mentions' do
+      let(:original_text) { "Attention: @ali has worked on this. @fred's work from @.ali-ce/group#9?" }
+      let(:expected_text) { "Attention: `@ali` has worked on this. `@fred`'s work from `@.ali-ce/group#9`?" }
+      let(:mention_extra_comment) do
+        {
+          id: 6,
+          note: original_text,
+          comments: [],
+          created_at: now,
+          updated_at: now,
+          parent_comment_note: nil,
+          imported_from: 'bitbucket_server'
+        }.merge(author_details)
+      end
+
+      let(:mention_comment) do
+        {
+          id: 5,
+          note: original_text,
+          comments: [mention_extra_comment],
+          created_at: now,
+          updated_at: now,
+          parent_comment_note: nil,
+          imported_from: 'bitbucket_server'
+        }.merge(author_details)
+      end
+
+      it 'inserts backticks around the mentions' do
+        importer.execute(mention_comment)
+
+        expect(merge_request.notes.first.note).to eq(expected_text)
+        expect(merge_request.notes.last.note).to eq(expected_text)
+      end
+    end
+
     context 'when the note has a parent note' do
       let(:pr_comment) do
         {
@@ -158,7 +184,6 @@ def expect_log(stage:, message:, iid:, comment_id:)
       end
 
       it 'logs its exception' do
-        expect(mentions_converter).to receive(:convert).and_call_original
         expect(Gitlab::ErrorTracking).to receive(:log_exception)
           .with(StandardError, include(import_stage: 'import_standalone_notes_comments'))
 
diff --git a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer_spec.rb b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer_spec.rb
index f403d534c7750d71d4a9045f74d17d98cace89ee..c89fc2ad1a260cfed32302fce7d79d41c3f5eae3 100644
--- a/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer_spec.rb
+++ b/spec/lib/gitlab/bitbucket_server_import/importers/pull_request_notes_importer_spec.rb
@@ -13,7 +13,6 @@
   let_it_be(:pull_request_data) { Gitlab::Json.parse(fixture_file('importers/bitbucket_server/pull_request.json')) }
   let_it_be(:pull_request) { BitbucketServer::Representation::PullRequest.new(pull_request_data) }
   let_it_be_with_reload(:merge_request) { create(:merge_request, iid: pull_request.iid, source_project: project) }
-  let(:mentions_converter) { Gitlab::Import::MentionsConverter.new('bitbucket_server', project) }
 
   let(:merge_event) do
     instance_double(
@@ -97,10 +96,6 @@ def expect_log(stage:, message:)
       .to receive(:info).with(include(import_stage: stage, message: message))
   end
 
-  before do
-    allow(Gitlab::Import::MentionsConverter).to receive(:new).and_return(mentions_converter)
-  end
-
   subject(:importer) { described_class.new(project.reload, pull_request.to_hash) }
 
   describe '#execute', :clean_gitlab_redis_shared_state do
@@ -167,7 +162,56 @@ def expect_log(stage:, message:)
           )
         end
 
-        context 'when the note has a parent note' do
+        context 'when the note has @ mentions' do
+          let(:original_note_text) { "I said to @sam_allen.greg follow @bob's advice. @.ali-ce/group#9?" }
+          let(:expected_note_text) { "I said to `@sam_allen.greg` follow `@bob`'s advice. `@.ali-ce/group#9`?" }
+          let(:original_reply_text) { "@bachhus I don't agree. See @ali's evidence cc @.ali-ce/group#9?" }
+          let(:expected_reply_text) { "`@bachhus` I don't agree. See `@ali`'s evidence cc `@.ali-ce/group#9`?" }
+
+          let(:pr_note) do
+            instance_double(
+              BitbucketServer::Representation::Comment,
+              id: 456,
+              note: original_note_text,
+              author_name: 'Note Author',
+              author_email: 'note_author@example.org',
+              author_username: 'note_author',
+              comments: [pr_note_reply],
+              created_at: now,
+              updated_at: now,
+              parent_comment: nil)
+          end
+
+          let(:pr_note_reply) do
+            instance_double(
+              BitbucketServer::Representation::Comment,
+              note: original_reply_text,
+              author_name: 'Note Author',
+              author_email: 'note_author@example.org',
+              author_username: 'note_author',
+              comments: [],
+              created_at: now,
+              updated_at: now,
+              parent_comment: nil)
+          end
+
+          it 'inserts backticks around the mentions' do
+            importer.execute
+
+            expect(Note.first.note).to eq(expected_note_text)
+            expect(Note.last.note).to eq(expected_reply_text)
+          end
+        end
+
+        context 'when the note has a parent note with @ mentions' do
+          let(:original_parent_text) do
+            "Attention: To inform @ali has worked on this. @fred's work from @.ali-ce/group#9?"
+          end
+
+          let(:expected_parent_text) do
+            "Attention: To inform `@ali` has worked on this. `@fred`'s work from `@.ali-ce/gro` ..."
+          end
+
           let(:pr_note) do
             instance_double(
               BitbucketServer::Representation::Comment,
@@ -185,7 +229,7 @@ def expect_log(stage:, message:)
           let(:pr_parent_note) do
             instance_double(
               BitbucketServer::Representation::Comment,
-              note: 'Parent note',
+              note: original_parent_text,
               author_name: 'Note Author',
               author_email: 'note_author@example.org',
               author_username: 'note_author',
@@ -196,10 +240,10 @@ def expect_log(stage:, message:)
             )
           end
 
-          it 'adds the parent note before the actual note' do
+          it 'adds the parent note before the actual note with backticks inserted' do
             importer.execute
 
-            expect(Note.first.note).to include("> #{pr_parent_note.note}\n\n")
+            expect(Note.first.note).to include("> #{expected_parent_text}")
           end
         end
 
@@ -223,18 +267,6 @@ def expect_log(stage:, message:)
           end
         end
 
-        context 'when the `bitbucket_server_convert_mentions_to_users` flag is disabled' do
-          before do
-            stub_feature_flags(bitbucket_server_convert_mentions_to_users: false)
-          end
-
-          it 'does not convert mentions' do
-            expect(mentions_converter).not_to receive(:convert)
-
-            importer.execute
-          end
-        end
-
         it 'logs its progress' do
           expect_log(stage: 'import_standalone_pr_comments', message: 'starting')
           expect_log(stage: 'import_standalone_pr_comments', message: 'finished')
@@ -376,18 +408,6 @@ def expect_log(stage:, message:)
           end
         end
 
-        context 'when the `bitbucket_server_convert_mentions_to_users` flag is disabled' do
-          before do
-            stub_feature_flags(bitbucket_server_convert_mentions_to_users: false)
-          end
-
-          it 'does not convert mentions' do
-            expect(mentions_converter).not_to receive(:convert)
-
-            importer.execute
-          end
-        end
-
         it 'logs its progress' do
           expect_log(stage: 'import_inline_comments', message: 'starting')
           expect_log(stage: 'import_inline_comments', message: 'finished')
diff --git a/spec/lib/gitlab/bitbucket_server_import/importers/users_importer_spec.rb b/spec/lib/gitlab/bitbucket_server_import/importers/users_importer_spec.rb
deleted file mode 100644
index 5519a829daab18a291b93caa211b239706d0a41a..0000000000000000000000000000000000000000
--- a/spec/lib/gitlab/bitbucket_server_import/importers/users_importer_spec.rb
+++ /dev/null
@@ -1,78 +0,0 @@
-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe Gitlab::BitbucketServerImport::Importers::UsersImporter, feature_category: :importers do
-  let(:logger) { Gitlab::BitbucketServerImport::Logger }
-
-  let_it_be(:project) do
-    create(:project, :with_import_url, :import_started, :empty_repo,
-      import_data_attributes: {
-        data: { 'project_key' => 'key', 'repo_slug' => 'slug' },
-        credentials: { 'base_uri' => 'http://bitbucket.org/', 'user' => 'bitbucket', 'password' => 'password' }
-      }
-    )
-  end
-
-  let(:user_1) do
-    BitbucketServer::Representation::User.new(
-      { 'user' => { 'emailAddress' => 'email1', 'slug' => 'username1' } }
-    )
-  end
-
-  let(:user_2) do
-    BitbucketServer::Representation::User.new(
-      { 'user' => { 'emailAddress' => 'email2', 'slug' => 'username2' } }
-    )
-  end
-
-  let(:user_3) do
-    BitbucketServer::Representation::User.new(
-      { 'user' => { 'emailAddress' => 'email3', 'slug' => 'username3' } }
-    )
-  end
-
-  before do
-    stub_const("#{described_class}::BATCH_SIZE", 2)
-
-    allow_next_instance_of(BitbucketServer::Client) do |client|
-      allow(client).to receive(:users).with('key', limit: 2, page_offset: 1).and_return([user_1, user_2])
-      allow(client).to receive(:users).with('key', limit: 2, page_offset: 2).and_return([user_3])
-      allow(client).to receive(:users).with('key', limit: 2, page_offset: 3).and_return([])
-    end
-  end
-
-  subject(:importer) { described_class.new(project) }
-
-  describe '#execute' do
-    it 'writes the username and email to cache for every user in batches' do
-      expect(logger).to receive(:info).with(hash_including(message: 'starting'))
-      expect(logger).to receive(:info).with(hash_including(message: 'importing page 1 using batch size 2'))
-      expect(logger).to receive(:info).with(hash_including(message: 'importing page 2 using batch size 2'))
-      expect(logger).to receive(:info).with(hash_including(message: 'importing page 3 using batch size 2'))
-      expect(logger).to receive(:info).with(hash_including(message: 'finished'))
-
-      expect_next_instance_of(Gitlab::Import::PageCounter) do |page_counter|
-        expect(page_counter).to receive(:current).and_call_original.once
-        expect(page_counter).to receive(:set).with(2).and_call_original.once
-        expect(page_counter).to receive(:set).with(3).and_call_original.once
-        expect(page_counter).to receive(:expire!).and_call_original.once
-      end
-
-      expect(Gitlab::Cache::Import::Caching).to receive(:write_multiple).and_call_original.twice
-
-      importer.execute
-
-      cache_key_prefix = "bitbucket_server/project/#{project.id}/source"
-      expect(Gitlab::Cache::Import::Caching.read("#{cache_key_prefix}/username1")).to eq(
-        { value: 'email1', type: :email }.to_json
-      )
-      expect(Gitlab::Cache::Import::Caching.read("#{cache_key_prefix}/username2")).to eq(
-        { value: 'email2', type: :email }.to_json
-      )
-      expect(Gitlab::Cache::Import::Caching.read("#{cache_key_prefix}/username3")).to eq(
-        { value: 'email3', type: :email }.to_json
-      )
-    end
-  end
-end
diff --git a/spec/workers/gitlab/bitbucket_server_import/stage/import_repository_worker_spec.rb b/spec/workers/gitlab/bitbucket_server_import/stage/import_repository_worker_spec.rb
index 1531b30089c9c2346cffc8232056c7fded81f6f4..7ea23041e791b3f442653457976c49c2a08e7e4a 100644
--- a/spec/workers/gitlab/bitbucket_server_import/stage/import_repository_worker_spec.rb
+++ b/spec/workers/gitlab/bitbucket_server_import/stage/import_repository_worker_spec.rb
@@ -18,25 +18,12 @@
       end
 
       it 'schedules the next stage' do
-        expect(Gitlab::BitbucketServerImport::Stage::ImportUsersWorker).to receive(:perform_async)
+        expect(Gitlab::BitbucketServerImport::Stage::ImportPullRequestsWorker).to receive(:perform_async)
           .with(project.id)
 
         worker.perform(project.id)
       end
 
-      context 'when the bitbucket_server_convert_mentions_to_users flag is disabled' do
-        before do
-          stub_feature_flags(bitbucket_server_convert_mentions_to_users: false)
-        end
-
-        it 'skips the user import and schedules the next stage' do
-          expect(Gitlab::BitbucketServerImport::Stage::ImportPullRequestsWorker).to receive(:perform_async)
-            .with(project.id)
-
-          worker.perform(project.id)
-        end
-      end
-
       it 'logs stage start and finish' do
         expect(Gitlab::BitbucketServerImport::Logger)
           .to receive(:info).with(hash_including(message: 'starting stage', project_id: project.id))
diff --git a/spec/workers/gitlab/bitbucket_server_import/stage/import_users_worker_spec.rb b/spec/workers/gitlab/bitbucket_server_import/stage/import_users_worker_spec.rb
index 1141d08729d356d844f4f70ef83e6d6325967330..dcc72c187f7c60617dfdf2766fc95a85e317c57c 100644
--- a/spec/workers/gitlab/bitbucket_server_import/stage/import_users_worker_spec.rb
+++ b/spec/workers/gitlab/bitbucket_server_import/stage/import_users_worker_spec.rb
@@ -14,77 +14,9 @@
 
   let(:worker) { described_class.new }
 
-  it_behaves_like Gitlab::BitbucketServerImport::StageMethods
-
   describe '#perform' do
-    context 'when the import succeeds' do
-      before do
-        allow_next_instance_of(Gitlab::BitbucketServerImport::Importers::UsersImporter) do |importer|
-          allow(importer).to receive(:execute)
-        end
-
-        allow(Gitlab::BitbucketServerImport::Stage::ImportPullRequestsWorker).to receive(:perform_async).and_return(nil)
-      end
-
-      it_behaves_like 'an idempotent worker' do
-        let(:job_args) { [project.id] }
-      end
-
-      it 'schedules the next stage' do
-        expect(Gitlab::BitbucketServerImport::Stage::ImportPullRequestsWorker).to receive(:perform_async)
-          .with(project.id)
-
-        worker.perform(project.id)
-      end
-
-      it 'logs stage start and finish' do
-        expect(Gitlab::BitbucketServerImport::Logger)
-          .to receive(:info).with(hash_including(message: 'starting stage', project_id: project.id))
-        expect(Gitlab::BitbucketServerImport::Logger)
-          .to receive(:info).with(hash_including(message: 'stage finished', project_id: project.id))
-
-        worker.perform(project.id)
-      end
-    end
-
-    context 'when project does not exists' do
-      it 'does not call importer' do
-        expect(Gitlab::BitbucketServerImport::Importers::UsersImporter).not_to receive(:new)
-
-        worker.perform(-1)
-      end
-    end
-
-    context 'when project import state is not `started`' do
-      it 'does not call importer' do
-        project = create(:project, :import_canceled)
-
-        expect(Gitlab::BitbucketServerImport::Importers::UsersImporter).not_to receive(:new)
-
-        worker.perform(project.id)
-      end
-    end
-
-    context 'when the importer fails' do
-      it 'does not schedule the next stage and raises error' do
-        exception = StandardError.new('Error')
-
-        allow_next_instance_of(Gitlab::BitbucketServerImport::Importers::UsersImporter) do |importer|
-          allow(importer).to receive(:execute).and_raise(exception)
-        end
-
-        expect(Gitlab::Import::ImportFailureService)
-          .to receive(:track).with(
-            project_id: project.id,
-            exception: exception,
-            error_source: described_class.name,
-            fail_import: false
-          ).and_call_original
-
-        expect { worker.perform(project.id) }
-          .to change { Gitlab::BitbucketServerImport::Stage::ImportUsersWorker.jobs.size }.by(0)
-          .and raise_error(exception)
-      end
+    it 'returns without calling the next import stage' do # no-oped. Will be removed in follow up https://gitlab.com/gitlab-org/gitlab/-/issues/508916
+      expect { worker.perform(project.id) }.not_to raise_error
     end
   end
 end