If anything has become certain over the past week, it is that the Todd Phillips Joker film is actually happening. On the other hand, the last news that has came out of The Batman was that the first act's draft has been turned in, revolving around a younger Bruce Wayne.
During an episode of The Superhero News Show, Mark Hughes, a writer for Forbes, broke that discussions have been made about setting the two films in the same universe. Hughes emphasizes that these ideas are in the very early stages, and though it is a rumor, he was approached with the information by two different sources. At this point, there is still a strong possibility that this may not come to light.
If these ideas do come through, Warner Bros. would have their hands on not one, but two DC Cinematic Universes. Though it may be cool, it will challenging for audiences to keep track of the titles and their respective settings. General audiences have a hard enough time understanding when films like Rogue One and Solo take place within the Star Wars canon. It would be even more challenging to juggle several iterations of characters in theaters during the same timeframe.