You give vendors far too much credit or don't quite realize how little they contribute to any non-Windows platform (macOS, AIX, Solaris, Linux, BSD, etc).If it's not getting changed in the handbook then don't complain when vendors don't release drivers for FreeBSD, because until the handbook is improved, FreeBSD's marketshare won't increase and vendors will have no concern about FreeBSD drivers.
Besides, check out Microsoft's documentation here:
https://docs.microsoft.com/en-us/windows/wsl/interop
C:\temp> wsl ls -la
You need to tell them that
C:\temp> is not part of the command and that vendors won't support them unless they change their documentation.