Rebel Wilson’s line was absolutely shock humor, but it was also an indication that the formerly-of-Barden Bellas weren’t getting any younger, and it really kicked off the events that followed.
Early on in Pitch Perfect 3, Emily invites the previously graduated Bellas to a show.
The former Barden Bellas think they’ve been asked to perform, but it’s in fact a miscommunication, and Emily wanted the gang to see the newly-formed Bellas perform.
The scene is sad for the now-adult Bellas, as they watch younger, hipper versions of themselves perform in front of an engaged crowd.