A batch of Batman rumors have hit the net that have previously been reported.
It's again said that Matt Reeves solo Batman movie will be standalone.
Back in August saw it reported that the Matt Reeves Batman movie would be set outside the DCEU continuity; however, Matt Reeves shot down the rumor and stated his Batman flick would take place within the DC universe, but subsequent articles have also stated the Matt Reeves Batman movie would be standalone.
Reeves himself actually said WB approached him with mention the Batman movie could be standalone.
“Well, I have a vision for a way to do something with that character that feels like it resonates with me personally, and a perspective that can grow out into other things. When they [Warner Bros.] approached me, what they said was ‘look, it’s a standalone, it’s not part of the extended universe.'”
Obviously if this is the direction of the Reeves Batman film, they will not be using Ben Affleck as Batman and will cast a new actor.
Regarding the future of Ben Affleck as Batman, which currently seems to be up in the air, it's possible Ben Affleck could appear in the Flashpoint movie if it is still getting made, and Batman On Film has the rumor Ben Affleck could appear as Batman in Suicide Squad 2.
It all more or less seems basically like speculation, and WB just recently made a bunch of changes to their executive leadership, so unless it's officially announced, consider everything a rumor for now.