Yeah, and in fact it happens that the best 4 teams is plenty enough. 12 is gracious overkill. Nobody ever said "wow, everybody thought this team was #5, but now we suddenly realize they're really the best". After the whole season, you just don't need that much precision at all. One of these days, a 4 seed will win, but it won't be because they really were the #1 seed and nobody knew it. Football is not like that.
Anyway, expect lots and lots of pearl-clutching about which team is #12 and which one is #13. Pretty lame stuff.