I mean, they could announce it but when they had the confidence to do so, overall there would be less complaints from the fanbase. They could announce what the expansion is about, lorewise maybe adding a new class/race and give as the art designs and preview of the zones, this would be enough, and then give us features along with the production of the x pack, in general I think small things matter to wow, like e.g. finding a group of players to kill a mini boss with you to get the quest done, or a little cut scene and a story to summarize the quest chain.. I guess you guys and I would enjoy something new if players stopped looking up spoilers all of the time everywhere, maybe that is why Cata lost so many subscribers overall, due to the annual pass, lots of players played the beta and then experienced everything so that when cata came out, doing the same content twice was boring and they probably players felt burnt out with the same content - Experiencing something for yourself is more fun, that is why I am stopping looking up and speculating because overall I will probably overhype myself and then be angry at blizzard that they don't meet my expectations which overall is my fault not theirs. I honestly think it will be hard since I am writing this on MMO-Champion which show leaks, models and spoilers very day (haha), but I'll manage, try it yourself!