Guessing boards with 16mb bios are SOL.
Hard to say really, it's up to the MB manufacturer. 16MB bios doesn't mean you won't get it, just that if you flash you may lose support for older gen stuff with a newer bios. It's a tough spot for a MB manufacturer because that's a bit of effort for a board they sold 3 years ago. On one hand, they want you to buy a new MB (profit, support, etc) and on the other they want happy customers who will buy boards in the future. I wouldn't be surprised if the MSI Gaming Pro Carbon ended up getting support, but it's really hard to know what the manufacturers are thinking at this point. Wish there was a list of what boards are expecting support, but I assume that won't be announced until the chips themselves are announced (or even later).