I find it unlikely they'd flip the entire process on it's head after all this and have everything start over from scratch, but who knows I guess.
The problem I see here is that they already agreed to hear the appeal before these maps were set, so it's easy to see them putting a stay on the maps while they hear the case, as they could ultimately decide the plaintiffs had no standing (?) to challenge the map. If they did hold the map, then no matter what, I can't see the map being used in 2016 even if they ruled in the plaintiff's favor. There would be no time for anyone to do anything. How can a candidate run a campaign for their primary if they don't even know who their constituents are yet? Not to mention the primary is held, I think, before the decision is expected and the filing deadline is in March.
Either way, I'm really hoping that SCOTUS does not hold back the map. The current map is clearly rigged and citizens of Virginia have already been subjected to this corruption for 2 cycles now. A 3rd cycle under maps found unconstitutional would be unbelievably unfair.