NVidia provides drivers, I'm using one on a Hackintosh now.
The golden question is if they would be allowed on an actual macOS image without hacks, Hackintoshes don't count.
What? The page linked has drivers for macOS. They work on a hackintosh and on any regular Mac. Nvidia wouldn’t release official drivers that only work on a hackintosh.
Today, the OP question was about a future Mac Pro.
They're meant for the older Mac Pros that could still have normal Nvidia GPUs in them. They just happen to work perfectly fine in Hackintoshes.
I don't see them doing otherwise.