According to a story by The Hollywood Reporter, about Ben Affleck's future as Batman, the actor is still attached to star in the developing Batman solo film (a project he was once going to direct), but that may not actually happen. Instead, sources are saying that the studio plans on starting a process to “gracefully” move on in a different direction without the Affleck, addressing the change in one of their upcoming projects.
Earlier in the year, not only did Matt Reeves replace Ben Affleck as the director of the solo Batman movie, but it was revealed a few weeks ago that Reeves doesn't plan on using any of the script that Affleck co-wrote with DC Chief Creative Officer Geoff Johns. THR also points out that Reeves has been developing plans for a full trilogy of movies, and that may not work out so well time-wise given that Affleck is now 45 years old and would likely be in his mid-50s by the time a three-feature arc wraps up. This obviously wouldn't disqualify him from the part, but the report notes the benefit of doing a soft reboot with a fresh face.
There is suggestion in the new report that Ben Affleck could continue to play Batman in “Justice League” follow-ups while the solo films star a different actor in the role, but that idea is also dismissed as implausible given that a “Justice League 2” could still be long off from now.