Paul Wernick and Rhett Reese revealed that Deadpool 2 originally had a much darker ending.
The scribes wanted to permanently kill off Deadpool's girlfriend, Vanessa.
---We originally did not save her. It was interesting ? we thought we might have to save her with the time machine, because the audience would be mad at us, but they were accepting of her being dead.---
The writers said killing Vanessa was a difficult decision but one they felt they had to make for the story.
Luckily, the two were able to kill her off and then bring her back in the end.