I thought similiar, recalling back to someone mentioning a GW manager saying that " they had seen a new black coach and it was amesome"
Is the part about stormcast being half the force speculation or someone spill some beans somewhere? I mean it wouldnt be the first time that the posterchilds werent in a box set, would it? Maybe Darkoath. They'd be human enough to represent I'd imagine. We'll see.