Wine's Project Leader Has Given A Blessing To The Wayland Effort
The engineers at Collabora have been making good progress on the Wayland driver for Wine to allow Windows games/applications to run on Wayland without having to go through XWayland while in the ensuing discussion on the latest version of the patches were the prospects or requirements around getting it accepted upstream.
Last week Alexandre Julliard as the project leader commented on the matter. Ultimately he's open to it being upstreamed permitting that it uses established Wayland protocols and doesn't resort to relying on workarounds or other hacks that compromise the ability to maintain it.
I'm not opposed in principle to having a Wayland driver upstream. In fact I started writing one myself many years ago... It got stalled when I realized there was essentially no way to do decent window management, and that the best we could do would be the equivalent of X11 desktop mode, where we manage the windows ourselves. I don't have the impression that the situation has improved in the meantime, or that there is any interest in improving it.
That doesn't mean it couldn't go upstream, but then there will be constraints on what hacks and workarounds you'll be able to do. For instance, it will have to stick to protocols that are standardized across desktops, without adding compositor-specific workarounds, just like we don't allow window manager specific hacks on the X11 side otherwise it quickly becomes unmaintainable.
I expect you'll find a much bigger impedance mismatch between Wayland and Win32, and that in the end you'll end up reinventing XWayland using Windows APIs. But if that's your idea of fun go ahead ;-)
With the blessing that Julliard isn't outright against such a Wayland driver, the discussion so far is indicating it will likely go through Wine-Staging first before maturing and working its way to upstream.