there were 3 flash movies... from the 90's tv showYeah by the time they got Spidey into the MCU there had already been two other iterations. So Iron Man having more of a role than J. Jonah Jameson or Norman Osborn was not as big a deal.
Ezra or no Ezra is another issue. The Flash has never had his own film at all when just almost every Marvel and DC superhero has.
Sure if you wanna get more of Flash world watch the tv show but its meant more for an epic blockbuster movie. I mean if Ant-Man can have a movie mostly to himself unfair to Flash.
If Keaton as Batman was a surprise cameo in a post credits scene that would be more appropriate.
Or just change the title.
