It's still unclear what Matt Reeves' The Batman will be. Apparently, it will be a DCEU stand-alone, taking place in an already established timeline with the same Batman - played by Ben Affleck - carrying the same post-Justice League baggage. That would no doubt delight a good amount of fans. Indeed, a lot of talk seems to be fixating on the positives of bringing Affleck back for The Batman.
He was great as the more muscle-bound Batman in Batman v Superman and stood out magnificently, and it's great to have the opportunity to see more of him in Justice League. Equally though, it's the right idea now to get rid of him for The Batman and to leave behind the Justice League time-line - at least for the stand-alone. Not least because keeping Affleck and old-man Batman means there is already a lot Reeves absolutely cannot do with his movie. His options are automatically limited.
When you think about it, it's actually pretty odd that Geoff Johns would even want to continue down this line with Affleck. He's spoken very openly about his desire to move away from deconstructing heroes, and yet the DCEU's Batman is a hero at the end of his career, pulled out of retirement, who has already dealt with a vast array of demons (both villains and his own inner ones). He's a walking opportunity for deconstruction, and there's limited space to "build him up" as Johns has suggested is the agenda now.
So isn't it about time they retired Affleck as Batman (at least in the stand-alone movies), and simply used him for Justice League ensembles? There's way too much we'd have to miss out on to accommodate him for it to be the right choice...