Canonically, the continuity of DC Films’ output is all over the place. Man of Steel was initially believed to be a straightforward Superman reboot, before it was announced shortly after the movie’s release that it was the launchpad for an entire shared universe instead, with Batman v Superman: Dawn of Justice, Suicide Squad and Justice League taking place in the same timeline.
However, the fallout from Joss Whedon’s theatrical dud saw the studio’s subsequent movies put less and less emphasis on the connective tissue, and now the Snyder Cut of Justice League has muddled things even further. Fans accept the HBO Max exclusive as official canon, but Warner Bros. doesn’t, while Joker and The Batman exist in separate realities of their own.
Matt Reeves’ reboot of the Dark Knight isn’t expected to cross over with the DCEU, but there’ve still been rumors that it might eventually, with a new report claiming that Robert Pattinson’s debut under the cape and cowl could be set on Earth-2, which would technically allow his Batman to interact with the likes of Jason Momoa’s Aquaman, Gal Gadot’s Wonder Woman and others once The Flash introduces the multiverse.
However, the report also goes onto say that WB are changing their minds about canon yet again, and with the exception of The Batman, all future movies and TV shows will be set in the same universe. When you factor in the nonstop barrage of speculation surrounding the future of the SnyderVerse, it’ll cause a migraine just trying to figure out how it’s all supposed to tie together, and in a couple of years, DCEU canon may have shifted dramatically for what would be the umpteenth time, regardless of whether Zack Snyder returns to the fold or not.