I always figured that the name grew from Misawa associating himself with the biblical figure Noah. After all, like Noah, Misawa led something of a mass exodus from All Japan. (And by saying "exodus," I'm not confusing him with Moses, so relax, all you Bible scholars out there.) He took all the talent he could get his hands on, bundled them up in his own promotional "ark," if you will, and set off on his own. Similarly, in the Noah myth, Noah assembled all the animals on the ark to escape the impending destruction of the world (the 40-day flood). In that sense, Misawa seems to be making a vague reference to the "destructive" influence of Motoko Baba. Either way, there's something of a structural similarity: a collection of beings escaping from an apocalyptic situation.