Unlikely? They didn't exactly get the Mac Pros out to everyone very well. I can see it being sold out for months. The market for this machine is quite large - arguably a lot larger than the one that fell to the Mac Pro 2013 - 'despite' being an all-in-one, this is the most powerful Mac to date. I know a lot of videographers who are readying themselves to purchase this machine on Day One and that's just a small market of creatives who will be after this.
We're most likely less than two months away from release, and yet we still don't know when it's coming out, what the price of each configuration will be etc. If they said, arriving, December 15th, which I think is a likely Friday release date, then at least we would all be like, "OK... that's the date"... it again feels like the 'pro market' just have to wait until December to learn anything more about a product that was announced a long while ago.
I know I'm being finicky and impatient, but it's a general feeling that we've all felt for too long prior to the announcement