I was and am adamant of the "console effect" benefiting PC GCN..
Covered here in this video from @Adored
https://www.youtube.com/watch?v=aSYBO1BrB1I
I know NV will never give up easily without a fight. And they can fight, they have a lot of money that AMD doesn't.
How NV fights this is quite easy, it's about buying the sponsor rights to the PC port of cross-platform games and ensuring GameWorks or PhysX is in the game to give their hardware and edge.
They do not need to do it for all games, just a few critical ones, like Rise of the Tomb Raider and again in Mirror's Edge. Games that are good and will become a benchmark for GPU performance. This skews the final summary towards NV just enough to make them look competitive among all the waves of GCN optimized ports.
It doesn't need to be a huge swing, Battlefront where R290X = 980, R290 > 970, now NV sponsors Mirror's Edge, we get R290X = 970.
The second way for them to fight back is making Pascal GCN-like in layout and warp optimizations. This includes fine-grained preemption capabilities so Pascal can switch between graphics & compute workloads instantly without a slow context switch. So GCN optimized or compute-heavy games do not negatively hurt their GPU performance as much. The next step of this will occur in Volta, with multi-engines so their GPU will excel in DX12 & Vulkan.