XWayland already exists and is the name for X.org running on Wayland, to enable X11 apps to run on Wayland desktops.
You may be interested to learn about wl-roots though. It's a project that I think originated from sway, and it aims to provide most of the low-level plumbing for writing your own Wayland window manager/desktop environment.
We could call it X-Wayland