This:
"When Windows 11 is installed on a device that doesn't meet the minimum system requirements, a watermark is added to the Windows 11 desktop. Notification might also be displayed in Settings to advise that the requirements aren't met."
My understanding is that Microsoft is simply providing visible notice(s) when a host system does not meet the required hardware specifications.
Not that Microsoft is "officially supporting" doing or otherwise recommending any such installs - whether the install works, partially works, or does not work at all.
End users seeing the watermark may call into question the installed OS and/or the build itself.
Caveat Emptor.