The following post contains SPOILERS for Once Upon a Deadpool.
The Fred Savage scenes are the only significant addition Once Upon a Deadpool makes to Deadpool 2.
I’m not sure why you would want a post that explains the differences between Deadpool 2 and Once Upon a Deadpool without spoilers, but I’m not here to judge your life choices.
(Deadpool full frontal is a no-no, but a song with a chorus chanting “Holy s— balls” over and over is apparently fine.)