I would love to have a 40-something Bruce (Lee Pace is still the ideal choice as far as I'm concerned), especially if he's already got Damian as a Robin. That's the correct age for that version of the character, imo.
BUT, I just don't see them going that way with this casting, especially given how Gunn has already pushed back against that notion when people took it as a given. "A few years older" than Superman is what he's looking for. 80% chance whoever they cast won't even be 40 imo.
Not so fast.
These are the three times Gunn has talked about Batman's age. Two of them were completely evasive when he was given a chance to be super clear in the subject (especially the last one) and the first one seems like he was giving a clear answer... until you actually begin to see what he's saying and notice that he was being ridiculously evasive as well lmao.
Much is to be said about "Gunnspeak" and how he sometimes says very specific things so they are taken as literally as humanly possible so people can't tell him "But you told us this x!" because he'll always say "No, I ACTUALLY said y"
And that one is a particularly egregious example of it.
First of all... referring to Superman's age as "just younger than his 40s"? Putting the word "MIGHT" in all caps?
I can already see from a mile away:
-@jamesgunn why do we have a Batman in his 40s? You told us he was only gonna be a couple years older than Superman!
-I said he MIGHT be a couple years older than a Superman that was younger than 40. I never said that he could only be a couple years older than a 30 year old Superman.
Giving himself an out with BOTH the fact he put the word "MIGHT" in all caps and that he only referred to Superman's age back then as "younger than 40". If he casts an older dude he can say "I wasn't lying!" because he wasn't.
And honestly the fact he's been asked about it two times after and was evasive makes me think that yeah guys in their 40s are in the cards lmao. He was explicit from the beginning he wanted a younger Superman and specifically younger than Henry Cavill. He has been vague as hell when it comes to Batman by comparison, and again, if you look at his other castings (Mr. Terrific, Guy Gardner) he seems pretty open to casting older dudes as superheroes. Which is not surprising since he loves the John Wick franchise which has Keanu being a badass in his 50s, and also loves the recent Mission Impossibles which have the same story.
My instinct is that, right now, prior to a script existing or whatever he's probably looking at a very broad age range and will consider anyone that's "old enough to be a father figure to young adults" and "fit enough to be Batman", hence his vagueness. But maybe after a script is completed it gets narrowed down. And quite frankly, I doubt that any script for a movie that features "characters of a extended Bat-Family" and deals with the theme of "Batman as a father" will narrow you down to a younger Batman. The story kinda begs for an older one and I have no reason to think Gunn would not be able to see that.
Even then tho, a funny scenario that could happen is he'll stick with looking at a very broad age range and screen test a dude in his 30s, another one in their 40s and another one in their early 50s. Which would be hilarious.
It'll be a while till the DCU Batman is cast tho. Unless god decides to have mercy on me and Gunn decides to cast him for the Arkham show, Waller or something first. (Which I think would be kinda smart, actually. It'll be very tough to get people excited for a new Batman in a movie so soon after Robert but if you build up to him first with appearances like that where he's cool and people wanna see more of him I think that could work as a way of leading up to Brave and the Bold as an event)
For the moment tho...
Respect and enjoy the Pace.