So for an actual non-root mount point, ntpath.ismount() returns True and with IO_REPARSE_TAG_MOUNT_POINT included ntpath.islink() also returns True. nt.readlink() returns the "\\?\Volume{GUID}\" path

Root mount points ("C:\\", etc.) do not return true for islink()

os.rename() and os.unlink() work on non-root mount points, but not on root mount points. So there is at least some value in being able to detect "this is a root mount point that acts like a file".

I'm not seeing why having both islink() and ismount() be true in this case is a problem.