It seems that Paul Dini, who was the writer for both Batman: The Animated Series as well as Rocksteady's two Batman titles, won't be working on the next Batman game.
According to a "Kinda hoped I'd be doing another Arkham game in London during the Olympics. Esp, as I had a good source for tx. Ah, well."by the writer,
This seems to indicate that Rocksteady chose not to hire Dini, as opposed to Dini no longer interested in writing for the games.
It'll be interesting to see if any writer at all will be penning the next Rocksteady Batman tale.