Wasn't Jim Sterling on a podcast recently, and said something to the effect of (paraphrasing): Someone is going to give BotW a 7/10, either Polygon or himself, and the internet is going to go nuts?
I don't know. The whole thing feels staged. We already know that devout Zelda fans lose their shit when any of the games gets a low score. Even low scores for Skyward Sword got some pretty harsh reactions. So giving this game a low score and poking the hornet's nest seems like an easy way to get publicity. The turnaround to putting around a video about the whole situation was pretty damn fast, as well.
It could be nothing, but it just feels too convenient.