For what it's worth, the ASRock B450M Pro4 that I got off Amazon last week came with a Ryzen 3000 sticker on the box and the UPC sticker had a "3". I had bought another one from Newegg a few months prior, it had "R2" on the UPC and no Ryzen 3000 sticker, but still had a BIOS which supported Ryzen 3000.
Of course, YMMV, perhaps I just lucked out in both cases. Though I didn't use any 3000 series CPU (2700X and 2700) since they were both cheap for 8-core CPUs.
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