Another fun reveal from DC's 2021 FanDome event was the first teaser trailer for the upcoming Flash film starring Ezra Miller. Like most early teasers, it's not much … but you do get a glimpse of the back of Michael Keaton's head, as he returns to the role of Batman for the first time in 20 years. Ben Affleck will also be appearing in the role of Batman in The Flash, because the movie is supposedly based on the 2010 Flashpoint storyline, where the Flash tried to change the timeline and ended up causing all kinds of other problems.
Presumably, they are both playing alternate reality versions of Bruce Wayne, in the same kind of meta-wink-and-nod as the upcoming Spider-Man: No Way Home looks to be doing. But maybe not. (Spoilers for a decade-old comic book that's already been adapted for TV anyway: the version of Batman of the Flashpoint universe was actually revealed to have been Thomas Wayne, because young Bruce ended up getting killed in that mugging. Martha — a woman of great importance in the DC Cinematic Universe! — ended up going mad with grief and becoming the Joker. So the Keaton casting could be a double-fake-out.)
The Flash is currently scheduled to be released on November 4, 2022…although the movie, too, has travelled through a time a bit. It was originally scheduled to be released in 2018, and has since gone through tons of directors, from Seth Grahame-Smith and Rick Famuyiwa; at one point, actor Ezra Miller even teamed up with writer Grant Morrison to take a pass at the screenplay, although that was ultimately scrapped, too. The current version is credited to screenwriter Christina Hodson (who did DC's Birds of Prey movie) and director Andrés Muschietti (the recent It remake duology).