Here's an thought, and it's probably total BS because I know absolutely nothing about law, but here goes.
If legal stuff is what's holding Dream Theater back from announcing the new drummer, could it mean that, legally, he is not yet in the band? As such, could it mean that he is not legally allowed to start recording with them (in case, I dunno, there's some kind of issue during recording)? Yeah, I know, it's a reeeeal long shot, but I'm just curious as to whether or not that would make any sense, legally.