get the impression WBros made this film by mistake
Affleck was supposed to star and direct (& write?) The Batman and was going to be based on Arkham Asylum or something but then he had all his issues divorce, drinking, rehab plus JL sort of bombed so he walked away from it all. so WBros mustve been like 'er..does anyone want to do Batman?' to which Reeves willve been jumping up and down hand raised going 'me!me!me!' so WB were like 'oh the Apes dude, ok sure' ..
But then think there was a change of studio management (whenever that happens stuff not already shooting usually gets thrown out/rejigged etc but by then The Batman was already in production).. and there mustve been like a Kevin Feige type assigned to DC movies as we getting The Flash doing the multiverse and bringing back Keaton not just a cameo but a major supporting role (that will probably lead to him heading a Batman Beyond movie) plus even Affleck is coming back..so this Batman movie is now just sort of 'there' and its like 'well the REAL Batman is coming back what we need this emo Batman for?'
.but right now WBros are probably like 'we'll see' and waiting to see how it all pans out..if The Batman turns out to be a classic that everyone loves like TDK and Joker and it makes a billion then emo Batman will be considered the REAL Batman it'll get sequels/trilogy and Keaton as Batman will just be a fun aside thing in The Flash and maybe a few other movies... but if The Batman is kind of 'meh' average box office then they'll probably press on with Keaton in Batman Beyond, etc