Just the old standards, RVA20 and below. RVA23 is the current standard, and they're just moving ahead with that because it's kind of pointless to keep all the other compilation cruft around when nobody is going to use it.

Whatever it supports I bet Jeff Geerling is on it

There isn't really any RVA22 hardware you'd really want to run a desktop on anyway, so it's a very logical decision. RVA23 is a much more sensible base - it requires Vector and Hypervisor.