Deadpool 2: 10 Things That Make No Sense
4. Saving Vanessa Via Time Travel
Travelling back in time to alter the past without a second thought for the wider ramifications is such a Deadpool thing to do, and sure enough, after Negasonic Teenage Warhead has worked her magic on Cable's device, he does just that.
The post-credits sequences show Wade Wilson jumping back in time to save Vanessa from a gangster's bullet. It gives the story a more upbeat ending, but it was a strange decision on the creative team's part since sparing Vanessa likely means that none of the events in the film after her death occurred, at least not in the same way.
Deadpool joined up with the X-Men because he was in mourning and therefore only crossed paths with Russell and later Cable as a knock-on effect of that. So, if those things didn't happen, does that mean Cable went on to kill Russell? Who knows?
The ending also undermines the scene where Vanessa tells Deadpool that they're destined to one day meet up in the afterlife, but his X-Force family needs him in the meantime. Because she survived, there is no F word for Wade to join up with.