We've published a short technical note in response to the new Mac Pro announcement:
New Mac Pro: What it means for Phase, Leaf
Also notably Capture One strongly leverages the video card for Open CL for both on screen adjustment ("responsiveness") and processing to JPG/TIFF. I fully expect the new dual video card option to provide a great Capture One experience.
As always, I'd recommend waiting for us to test rather than assume. We'll have one the moment their available.
This new Mac Pro sure looks like a big winner to me. Though the lack of internal upgradability is a bit disconcerting.