I can see it happening nowadays. We have the technology, and I believe there was a script floating about at one point in the past few years. Batman Beyond was pretty popular when it was on, and has remained popular enough to get representation in several games and comics, so DC is still willing to support it to an extent.
The only question is whether or not they’re willing to push a character that’s not Bruce Wayne Batman, or Superman. That’s the greatest hurdle to overcome, what with the terrible reception of the last non big-3 DC movie (Green Lantern) and DC’s reluctance to make one of their biggest franchises into a movie (Wonder Woman).
DC could do it. They should do it, I’d say. The only thing keeping them back is their own issues and stupid marketing decisions (though many of those are on the shoulders of distributors and networks. I’m looking at you Cartoon Network)