That may not be necessary for X570 or B550 boards. According to hardware unboxed, an update was released in July/August that enables them to boot with Ryzen 5000 CPUsMake sure to buy a motherboard that allows flashing without a cpu. Or you may find you need a older cpu to flash it before you can use the 5000 series. Look for ones that have a Flashback feature or whatever the manufacturer calls it.
OR make sure the motherboard is already flashed for the 5000 series.