Nested Virtualization is not a new idea. In fact, we announced our first preview of Nested Virtualization running on Windows way back in 2015. From that Windows Insider preview to now, Nested...
Updated Jun 12, 2020
Version 2.0
Blog Post
Hi GuillaumeIT64, the feature hasn't arrived in the consumer release versions yet. Only preview builds from 19636 have this and Windows 20H2 is 19042. The current dev build is something like 20257 but it's far from reliable enough for everyday use.
Will be more optimistic when the beta channel gets past 19636 (in fact would probably take a chance and install this) but there has been little if any talk from Microsoft since this blog post was published. I wish they would just tell us something.
So - if you're adamant that this is a deal breaker, you're either buying an Intel chip or going with VMWare, which already supports AMD nested virtualisation. I've had a play with this and it appeared to work (at least booting nested Hyper-V VMs) but I rely on Hyper-V for work and it really didn't like nested VMWare and needed disabled before anything would work.