The closing credits made me gasp, as it contained a moving tribute to Stan Lee, one month after his death. He even answers a question about his own death. Someone posted the tribute here: https://www.youtube.com/watch?v=BI6KbrpKbdA

Once Upon A Deadpool is the December 2018 PG-13 special edition of Deadpool 2. It adds Fred Savage in Princess Bride parody scenes for more comedy. It was a two-week limited release with $5 of each ticket going to a cancer charity, as arranged by Ryan Reynolds.