Michael Keaton, who gifted us with cinema's most bug-eyed insane Bruce Wayne in Tim Burton's Batman and Batman Returns, will reprise the role of the Dark Knight for The Flash movie starring Ezra Miller. According to The Wrap, Keaton's return will be part of The Flash's attempt to introduce the audience to the concept of a DC Comics multiverse.
The film, according to the report, "sees Ezra Miller’s Barry Allen travel back in time to prevent the death of his mother. The result? Allen inadvertently creates another universe protected by Michael Keaton’s Batman, now 30 years older."
The report notes that conversations are in very early stages, and the actual size of Keaton's role is up in the air. But essentially, the actor's presence is a way to introduce the idea that there is no "main" DC Universe, just many branches on one tree. So the same universe that saw Keaton's Batman do battle with Jack Nicholson's Joker exists, as does Christopher Nolan's Dark Knight trilogy universe, as does the universe in which Arthur Fleck (Joaquin Phoenix) became the Joker, etc etc. Reportedly, Keaton's presence won't at all effect The Batman, Matt Reeves' upcoming film that sees Robert Pattinson putting on the cape and cowl.
The Flash—which suffered a long and bumpy road to production, including one point where Miller himself was writing a script just to keep the project alive—will be directed by Andy Muschietti, the filmmaker behind Warner Bros.' hit adaptations of Stephen King's IT. It's long been rumored that the film will borrow from the comics' universe-hopping Flashpoint storyline, with this Keaton news offering even more evidence. It's interesting that, essentially, WB is just keeping its options open for the future, especially after the studio announced that Zack Snyder's cut of Justice League will debut on HBO Max. If The Flash establishes the idea that all DC universes are fair game, who's to say Snyder's story couldn't continue alongside standalone films like The Batman?
The Flash is tentatively scheduled to hit theaters on June 3, 2022.