I actually have no idea! Reading this article it seems like Asus may release more refreshes of their b450-line (an atx option would be nice).
Yes! It's about the same price as the b450 mortar that I was looking at prior to finding out about this board over here and it seemed like a good option to me. According to a post on chiphell, it seems to use the same vrm as the tuf plus and it has a 256mb chip which could be nice in the future.