I don't think it's a "hold up, we need another week for the game," announcement. Due to the nature of the tweet, this sounds like more like a "hold tight, retweet this, we'll get you the dates promptly."
They do this sort of pointless teasing on Laura and Job's Twitter all the time, even for something like ONE screenshot.
If it is the other alternative, I imagine that there will be a lot of angry posts from childish WD fans crowding the Community, making it a worst nightmare for the moderators. But likely, we'll still have the game before Christmas. It's always been that way.