Yeah Batman/Bruce being in his 40s makes more logical sense, franchise and film earning wise. If Snyder and WB truly want Batman back into the fold for a solo film reboot franchise after BvS and JLA, they'll need Affleck to be at a good age where they can make a solid contract for him for about a couple films plus other appearances as the character. Plus a way so he can do his own projects outside the Batman stuff since he loves directing now.  Also old age make up and not just gray hair doesn't always work out unless they want to go backwards in time with the eventual new solo films. Which means that the full Dark Knight Returns concept will only use certain elements to affect BvS's story. Very curious on how they are going to tease the Robin aspects and there was a death in the Bat family. I'm all for that. There are rumors going around that he may produce and show run the new Batman films and even JLA with Snyder. He was originally chosen to direct Justice League as a full film that was disconnected from the Dark Knight trilogy, Nolan, and other aspects before the relaunch with Snyder's Man of Steel in 2013. He already has his "Argo" writing partner re-writing BvS's script from David Goyer which is a good sign. Warner Bros. reportedly loves the newer script and wants the writer to scribe JLA too. The reports you mentioned all depend on what the full trailer looks like and how this upcoming movie goes with fans and critics in a few years.

Also the release date has been shortened from May to March 25th 2016. So it's not on the same date as Marvel's Captain America 3. It's actually a good move on WB's part since it will allow a wider release, more exposure, and not much competition. Also signs point to a good productive film shoot too. According to the article link below and various sources online, They announced some dates for various movie slots. Some of them include JLA, Shazam with Dwayne "The Rock" Johnson, the film adaptation of Neil Gaiman's Sandman produced by Joseph Gorden Levitt and written by David S. Goyer in collaboration with creator Gaiman (rumors are going he didn't finish the original BvS script because he wanted to focus on this and other projects, not sure. The guy has an ego.), Wonder Woman solo movie, Man of Steel 2 or 3 if BvS isn't the true MoS 2, Batman solo flick, and maybe a Green Lantern reboot team up with the Flash. The other dates could be non DC properties that WB wants to produce into new franchises.

http://www.nerdist.com/2014/08/batman-v … -revealed/