X-Men: Dark Phoenix, even publicly itted that he wanted to use the latter movie as a way to correct mistakes made in X-Men: The Last Stand.
Directorial duties were handed to Brett Ratner after several other directors left the project. Ratner had been considered to helm the first X-Men film years earlier, a movie that went through an even longer development stage, before it was offered to inappropriate behavior by Ratner, who has since been accused of sexual misconduct.
While Ratner was the final choice for director, there were quite a few before him. Several people were rumored to be up for consideration, a few turned it down, and there was more than one who were actually attached and did some pre-production work. The list begins with the director of the first two installments of the franchise: Bryan Singer. The King's Man, eventually signed on for the movie, even casting some of the major roles, but was forced to leave the project just weeks before filming began. Between the time Singer and Vaughn worked on the movie, there were even more directors discussed.
Hugh Jackman reportedly wanted A Good Day to Die Hard's John Moore was under consideration right around the same time Ratner was finally chosen as well.
All of these directors would have presented a X-Men: First Class a few years later. The future of the X-Men remains in flux with Disney now owning them and having to decide if and how to integrate them in the Marvel Cinematic Universe, though it remains to be seen whether any of these directors will get the same chance again.
