There's still a lot of uncertainty surrounding DC Entertainment and Warner Bros.' next plans for the Batman movie franchise - in fact, San Diego Comic-Con 2018 came and went with nary a reveal about the project, which is coming from Dawn and War for the Planet of the Apes director, Matt Reeves. Rumor continues to be the only thing to go on - and the latest one states that The Batman is going to be drawing from the Batman: Year One comics for its storyline.
Revenge of the Fan has an extensive breakdown on what's going on with The Batman, and a major part of that report has to do with the film's casting goals, as related to its setting. According to RotF, Warner Bros. and DC are now looking for "a Bruce who's 15 to 20 years younger, and is meant to be 25 to 30 years old in the story Reeves wants to tell." This is supposedly to find a Bruce Wayne who will be the centerpiece of a storyline based on Frank Miller's "Year One", according to RotF:
"In short, if Batman v Superman bore a passing resemblance to Frank Miller's The Dark Knight Returns, then The Batman will bear a resemblance to Miller's Batman: Year One."
The report also openly admits what most fans will probably point out: we've seen "Year One" adapted for film before. Chris Nolan's Batman Begins carries a lot of "Year One" in its DNA, and the actual storyline was adapted into a DC Universe animated feature in 2011. So, if this rumor is true, what will be needed to distinguish Reeves' film from other "Year One" adaptations will be a very different take on Batman's early career.
As RotF notes, this rumor does synch up with the latest reports about The Batman - namely that a production crew is being assembled (a sign that a story and script have been completed); the film will cast a younger Bruce Wayne as a soft reboot; and that The Penguin will be one of the villains. The latter villain rumor is especially relevant, as in the DCEU continuity of Justice League has already established that the biggest threats in Batman's early career were "Exploding Penguins." It's a thread that could connect back to Bruce Wayne first returning to Gotham to create The Batman, and having Oswald Cobblepot / Penguin be one fo the first crimelords he has to confront.
All of the above paragraph is speculative, of course, but there is a certain logic to DC/WB giving their Batman film franchise this sort of breathing room, and allowing it to be more standalone and grounded than the current Justice League continuity. That's exactly what WB supposedly wants, so don't be surprised if we start to get firmer confirmation that the "Year One" scenario is true.
Upcoming DC Extended Universe films include Aquaman on December 21st, Shazam on April 5, 2019, and Wonder Woman 2 on November 1, 2019.