While both X-Men: Apocalypse and X-Men: Dark Phoenix were massive disappointments, two X-Men shows proved that the franchise can be used properly. The Gifted was a great show that was cut early, while Legion will supposedly end the way showrunner Noah Hawley planned, which is great to hear. Though both shows are heavily X-Men-influenced, neither of them were set in the same universe as the movies.
However, showrunner Noah Hawley did consider making a connection to the older movies as he mentioned wanting to get Patrick Stewart to reprise his role as Charles Xavier for Legion season 3. That would have been one hell of a way to gain interest for the show since we haven't seen Stewart as Xavier since Logan.
Speaking with The Wrap, here is why Hawley eventually decided against casting Stewart:
"We're going to have to meet [David's] parents eventually. Nobody fought us on it. There was a question obviously about what age is he? What's the model? Is he the McAvoy age? Is he Patrick Stewart age? Should we try to get either of those actors to do it? Ultimately, I felt like we established our own alternate reality here on ‘Legion,' where it's both 1964 and the future… I think I felt like the younger Xavier was actually more consistent with the timeline. But there's something about David, if David meets his father and his father is his age, I think there's something interesting about that."
Though it would have been nice seeing Stewart in the Professor X chair again, Harry Lloyd ended up being a great choice to play as young Charles Xavier. With this being the final season, his eventual confrontation with David should be an epic one.
Legion season 3 currently airs on FX.
Read:Josh Brolin Has Contacted Marvel Studios About Cable's Future