Windows supports virtualization on the 8 Gen 3 only because they use a custom setup to load a signed binary blob ("applet") into the EL2 hypervisor, whose signature it is is hardcoded to accept, and that blob/applet then can be used by Windows as a kind of shim into EL2-land to spawn VMs, etc. But Qualcomm's hypervisor is always present and enforcing its security policy.
In practice every single modern system is running tons of binary firmware blobs, it's mostly where you draw the line on functionality and isolation of components (security, integrity, availability.) Here, Qualcomm does intentionally reduce some functionality, which is pretty bad when you consider that the UEFI spec for ARM mandates EL2 handover, I think, and they just ignore it.