He appears in some not all, he hasn’t been any of the Xmen movies since the first one.
X-Men movies aren’t from Marvel Studio, Fox owns the X-Men.
Here’s a picture for anybody curious on who owns what. And feel bad for Lionsgate who paid money for Man-Thing:
http://wac.450f.edgecastcdn.net/80450F/comicsalliance.com/files/2014/02/tumblr_n0sbtcJKyr1qa0uujo1_1280.png