The thing is, if that's all they're going to do, I don't really see the point. Signaling that the play stands already sends that message. There's no way for those in attendance to know the reason a call was or was not overturned. Signalling the play stands does not automatically mean there wasn't conclusive evidence. The weird thing to me is the crew chief has nothing to do with the decision in NY. Why not give NY a hot mic to the stadium to make his announcement? It's probably just technically simpler to have the crew chief explain the decision.