My employer, Red Hat, has been in close talks with NVIDIA with Wayland, and this has been brewing for a while. It's not really a secret or anything what's going on, and since Wayland has wanted to support NVIDIA, it's better they tell us now rather than in six months.
James Jones, Aaron Plattner, and the rest of the team at NVIDIA have actually been very friendly and open. We want to make sure our approach works with them, and I think everybody is happy with the relationship here.
We put together a fast plan to make Xwayland work in the short-term (we're going to support a loadable "DDX" like wf86-video-nvidia), and we're going to see if we can solve the issues that mean they have to have a DDX to bring up GLX direct rendering: it's actually backwards-compatibility for stuff that's broken by the FOSS stack. They're going to see if they can open up some of their internal testcases and tell us what backcompat behaviors they need to support, and we're going to see if we can modify the FOSS stack so these benefits are available for everyone.
And then we can build a new system that handles all of that into Xorg and Xwayland, and synchronziation in their DDX can just vanish and go away.