So, either Marvel could age up the characters in makeup, which seems unlikely, or they could continue the continuity with a new set of actors, such as the original X-Men cast.
The latter doesn’t seem likely, though, given the bulk original X-Men’s cast is approaching or beyond 50.
For years many have begged for Hugh Jackman’s Wolverine to appear in an Marvel Cinematic Universe feature, but it’s just not a realistic dream to hold anymore.
Plus, let’s remember that, no offense to the rest of the cast, the two main people most fans would want to return are now dead in the X-Men timeline.