Ben Affleck has said he has not been signed for any DCEU film past the first Justice League and that The Batman will not move forward until the script has been perfected. Because of the multiple issues he has had with it, it may be shelved and recasting could happen if no progress is made. I personally don't believe it, though there is a slim chance. Though I didn't jump on the bandwagon against Ben, Miller, Gadot, Eisenberg, or Leto when they were castes, I would say whoever the replacement would be is not good enough for the role.
Crackpot Theory: Will Smith is sabotaging the film so he can replace Ben as Batman like he wanted to.