Here's the thing; Had this been an Intel launch, based on their recent history, zero 300/400 chipsets would work with Zen 2. Since it is AMD we have options. Stop looking for a negative where there isn't one.
you make it sound as if I wouldn't point out the problem if it was with an intel product...
I almost always buy the lowest end chipsets that's were my interest in particular for this comes from,
and one of the reasons I celebrated AM4 was because it was supposed to be supported by new CPUs until 2020 (and this was announced alongside Zen years ago), they never clearly excluded A320 before, I'm trying to understand the reason behind this exclusion but I'm not finding a clear answer so far, that's all.
power delivery seems to be equivalent in many a320 and b350 boards and there are 65W Zen2 CPUs, also it looks like a320 uses the same "bios" type as some b450 boards at least in the ones I checked from Asus