I also have an email into EVGA customer service to get more information as a follow up to a phone call I had with tech support on this topic.
My question back to them for reference;
"Thank you for your email. If you could provide some additional details on what EVGA has found regarding the GA series of PSUs and the RTX 3080/90 compatibility that would be helpful. I was told on the phone this morning that there are certain combinations of hardware that may cause issues. Can you please elaborate on what those might be?"
I'll let you know if/when I hear back on this one.