More than a few folks have said Apple should stick to their 2013 'script' ( have to dog and pony at WWDC , etc. ). It really isn't beneath them since they have done it before.
If Apple has been running a rigid "just in time" set up then that may not happen. if they have been inventorying ( or making/paying suppliers ) to inventory for a couple of months parts then maybe.
Even at this highly price there is quite likely going to be a demand bubble that Apple supply can't hit for the first several weeks. If there is only 1-2 standard configurations there is a pretty good chance with this market demographic that there will be a big gap between what Apple could have completely pre-built and what is ordered.
P.S. In the 2013 script the "old" Mac Pro had been turned off by this time. The counter on the "just around the corner" is the 'buy' button still being active on the 2013 Mac Pros.
https://www.apple.com/shop/buy-mac/mac-pro
if it was super close Apple could just turn that off. It is boggling why they would even want it on at this point.
If you need it, you need it. I can't imagine they've been selling many Mac Pros these past few years, but it's better than having no option at all in the space.