>it'd offer a solution to keeping niche HW running

Preservation. It ensures WinNT survives as a platform even if Microsoft abandons it, which some would argue the present state of Win11 counts as doing.

If MS abandons WinNT, then people will likely continue to use the existing versions of Windows which are out there for any existing software (just as people continue to use MS-DOS and Win 9x for old games and software).

As for new software - I think it's open to debate just how much new Win32 software will be created after a hypothetical abandonment by Microsoft of Windows.

Windows 11 is the enshitification late stage advertisement economy product that no one asked for, and everyone in the C Suite at Microsoft is excited about. Probably the only thing they are more excited for is yet another terrible branding decision.