They can't order them to do anything. The game will receive a T rating, and it'll be fine with it. Nintendo censors less and less, and with this game, after the success of Melee, they won't touch a thing.
There's some pretty graphic content in Nintendo games. The re-deads are an excellent example. They literally latch on and suck the life out of you. When Mario drowns in his 3D games, it's pretty graphic, too. In the original Pokemon, there was a ghost tower for the souls of burdened dead pokemon, and that's pretty heavy for a game for young children, considering in battle, Pokemon only faint. Draygon leeches Samus pretty well, also, despite the power suit.
You're being a hypocrite. A bad one at that. You've seen this stuff happen to these characters all the time, and now that it's slightly more realistic, it isn't considered ok? I mean, we already had grabs. Heck, Yoshi even chewed on people in his mouth! That isn't something that appalled you? Cartoons can be more violent than have the stuff out there. Oh, Bugs just shot off Elmer Fudd's head with a shotgun, but it's ok, because it's a cartoon. Well, this is a video game. Snake is going to snap someone's neck. We've seen them shot, falling off cliffs, shocked, burned, sliced, diced, exploded, thrown at with random objects, grabbed, eaten, beaten senseless, and more, so I don't see the problem. This isn't any worse than grabbing someone and slapping/beating them like in Melee.