In the last video chat Ross said that he is interested in seeing if WSL2/WSLg (WSL from now on) can somehow be used to replace Windows shell with some Linux DE. So that he would have some Windows-Linux hybrid.
It probably isn't possible to use WSL as a full shell replacement like with other Windows shell alternatives. But from what I see, it is possible to run and display some DE as it's own application, so visually it's similar to virtual machine or remote desktop.
As far as I know, WSL does allow running Windows programs from within the Linux environment. Not exactly sure how that is done and what kind of programs can be started. But it is there, and that makes WSL be much more fitting for creation of Windows-Linux hybrid than it would be say Linux running in VirtualBox using "seamless mode".
Even if it is possible to get some desktop environment running well, there is still an issue of getting Windows shell out of the way, making it use absolutely minimum amount of resources, and re-implement the functionality in WSL desktop environment.
There are many people with low-spec machines, so someone probably already stripped Windows 10 shell down to bare minimum, but there probably aren't many people who made WSL understand the full capabilities of the Windows host. Things like having XDG-Open point to Windows programs for relevant files and URLs, having shortcuts in Linux guest that open host's Control Panel or other settings, etc.
I think that this idea of Windows-Linux hybrid is interesting, and should be explored further.
Few relevant links that I found when doing a quick search about this topic:
https://github.com/NathanCastle/BootShellCredentialProvider (looks outdated and abandoned)
https://www.youtube.com/watch?v=8SuERIEJJUA
https://github.com/microsoft/wslg
https://sourceforge.net/projects/vcxsrv/