Asus x570 Mobos. Bios upgrade without processor

True

Been getting mixed messages.  hoping someone here can say for SURE .  Planning on camping out for 5900x  this week .   will i be able to flash an assue prime or tuff gamming mobo to newest bios to support zen 3 without a zen 2 processor these don't have a bios flashing button..     the manual is kinda veuge on its build in bios updater if i can get at it with a not currently ccompatible CPU or no CPU installed.  Will be real irirated if i have to drive back to store and pay the tech center to flash it for me one of their cpus

Ent

I don’t think so. Asus does have “USB BIOS Flashback(tm)” on some of their boards, but I can’t find it in the manual for the TUF Gaming. I didn’t look for the other board because it’s an even more basic model so I doubt it does. 

Also the boards aren’t listed here https://www.asus.com/us/support/FAQ/1038568/ but I’m not sure how up to date that article is.