With the second film in the Harry Potter prequel series set to film during this summer, the prognosis doesn’t look great that The Flash will be able to meet its current March 16th release date in 2018 with all of the post production involved with a big blockbuster of that ilk.
During his press rounds for his current project, Alien: Covenant, Billy Crudup noted that Ezra Miller’s schedule is complex, and he’s certainly not wrong in that respect.
Short of becoming a faster-than-light being himself, DC could be cutting it close to try to make it happen.
In addition to playing Barry Allen, and his supersonic alter ego, Ezra Miller is also involved in a little franchise by the name of Fantastic Beasts and Where To Find Them.