The Green Bay Packers actually do their own singing. They did not learn their choreography until the night before filming.
The Green Bay Packers got the chance to appear in the film after offensive lineman David Bakhtiari sent a tweet to director Elizabeth Banks, telling her that they were big fans of the first The Hit Girls (2012) film and would love to appear in a sequel.
Improvisation was very common on the set.
In the original script, Fat Amy had a random love interest. It wasn't until the first table read that Rebel Wilson and other producers suggested that Fat Amy should be with Bumper, after their chemistry in the first film. Rebel Wilson stated that she "couldn't imagine anyone else" beside Adam DeVine playing her love interest.
Real acapella groups were used during filming, including Pentatonix (winners of The Sing-Off season 3) and Penn Masala (who have released 8 albums and sung for President Obama).
Kay Cannon: the writer of both films appears as a news reporter after Fat Amy (Rebel Wilson) flashes President Obama.