The last film Lesslie worked on was “The Hunger Games: The Ballad of Birds and Snakes”, a prequel to the popular book adaptations by Suzanne Collins. Previously he collaborated with Justin Kurzel at his “Macbeth” and “Assassin's Creed”. He also wrote the third part “Illusion”which will hit theaters in 2025.
In addition to Lesslie, producer Kevin Feige will certainly be associated with the X-Men film. Apart from that, we don't know anything about the cast and director. However, this will not be the debut of mutants in the Marvel Cinematic Universe. They were mentioned or appeared in cameos in earlier productions.
The main character of “Ms. Marvel” turned out to be a mutant. An alternate version of Charles Xavier, played by Patrick Stewart, appeared in “Doctor Strange in the Multiverse of Madness”. In turn, Beast (Kelsey Grammer) appeared in the post-credits scene “Marvels”. It is also waiting for its premiere “Deadpool & Wolverine”in which Hugh Jackman will return to the role of Logan and will also make his debut in the Marvel Cinematic Universe.
The X-Men have been on a roll lately. The series, a continuation of the animation from the 1990s, turned out to be a hit on the Disney+ streaming platform. It also received great reviews. Work on its second season is very advanced.