They aren't going to be worried by the 8.3 stuff, there's probably a way for them to talk about 9.0 without spoiling 8.3, it would be honestly a bit silly for them to do that. When they introduce 9.0 at BlizzCon, whatever the expansion is about, we'll get a story behind it, perhaps not how we get there, but the general basis of what the story is about for 9.0.