That's stupid.
I am pissed off too.
Please, if you are already a new MacPro owner, send at least 2-3 feedback to Apple, both to their OSX feedback site, and MacPro feed back site, just google up "Apple feedback"
And repeat your feedback every 10-15 days or so, until there is some sort of answer, announcement. I keep doing it, as I paid over 5K (in pounds..) - but not to use my Mac as Windows
That would be the joke of the year.
And yes, luckily the hardware seems to be ok, capable handling super large scenes, but much better in Windows.