Hi,
There should not be an issue with running Windows 10 rev 20H2.
FWIW I run 21H1 Windows insider preview down here as a VM and have run Windows insider preview software for long, including what is now 20H2.
One thing to make sure though is that your VM is using the latest virtual hardware.
You can find that under Settings -> Compatibility
It can only be changed with the VM shut down.
You might be able to get away with hardware version 16, but I would not run versions before that for a current Windows 10 VM.
hope this helps,
--
Wil
