Actually, that's not accurate.
ANY motherboard with a "Ryzen 3000 ready" sticker on the box will have already been updated to a compatible BIOS version for Ryzen 3000 series CPUs and will be GUARANTEED to work with them. Any motherboard that doesn't have one, and isn't a "Max" model, won't be guaranteed and will be a crapshoot as to whether it has BIOS support or not. It's LIKELY however that if there isn't a sticker on the box, then it has not been updated and won't be compatible. The only way to know that for certain is to buy at a local retailer and LOOK at the box, or ask the online retailer via phone or online chat, but in that instance as I said you may or may not get accurate information.
You can also reach out to specific...