Director Tim Miller said he exited Deadpool 2 because he didn’t see eye-to-eye with star Ryan Reynolds on the creative direction for the sequel, which, if Miller had his way, would have featured Fantastic Four’s The Thing, a more “comic accurate” depiction of Cable, and Morena Baccarin’s Vanessa Carlysle becoming Copycat.
In an appearance on The Playlist’s Fourth Wall podcast, Miller revealed his Deadpool 2 would have had a cameo of “The Thing throwing down with Juggernaut.” (Colossus ended up doing that in the final version of the film directed by David Leitch.)
Miller also wanted a more comics-accurate depiction of Cable, with the mutant from the future being 6’7″ in the books — something joked about in the final film at Josh Brolin’s expense.
Source: IGN.com The Thing Was Originally Supposed to Be in Deadpool 2