Two stories about upcoming DC Comics movies may at first appear to be unrelated, but if you put the pair of them side by side it unlocks a greater truth about what's coming next in their fledgling film universe.
The first story, as reported in The Hollywood Reporter, is that WB wants to replace Affleck as the Caped Crusader, as they feel he's too old to start a franchise of Batman standalone movies that by the time are done he would be in his mid 50's. Which of course, Robert Downey Jr is that age and still owning it as Iron Man for Marvel, but Batman is a different animal all together, much more physical role, so I understand where they are coming from with that.
I know there's been a lot of haters of his casting ever since it was announced, but I've enjoyed his performance, and would put him as one of the better Batmen at the end of the day.
The interesting part of that article comes from when they bring up that unlike in previous Batman recastings over the years, there will be an in universe explanation for the casting change that will make sense.
The next article, while seemingly a separate piece of news all together, puts a great picture together if you're a fan of the source material. That is of course, that the upcoming movie of The Flash will be titled and based off of the Flashpoint storyline from the comics. In this story, Barry Allen goes back in time to stop Reverse Flash, his arch nemesis, from murdering his mother, which sets off a chain of events that alters the timeline drastically.
One of these effects is that it reset the timeline in the comics, called The New 52, and some people got significantly younger due to the altered timeline, such as Green Arrow. I think, I really think that this is how we get a younger Batman. Really any casting they want to change post Flashpoint could be redone if they saw fit, and it would make sense, but I think this is how it's going down.
The first article brings up others who've worn the cowl in the comics, like Dick Grayson or Jean Paul Valley, but I don't see WB investing money into a Dick Grayson Batman movie, so this is the most likely future of the DC films.