During the end credits, there is a screen recording of Bo Burnham's editing software and if you look in the top right corner you can see he was editing these Outtakes at 3 AM on May 29th. One day before releasing them.
This outtakes special was released exactly one year after the original Netflix special
Bo Burnham had two front teeth accidentally knocked out as a child, which is why two of his teeth are discolored when he is testing the black light. Artificial teeth often do not fluoresce depending on what material they are made of, while real teeth naturally fluoresce.