Dont bring up "we work with..." BS here, it has nothing to do with what they do on this patch.
They said that async was only enabled on GCN cards, and that they where doing this to improve perf on old cards(that seems not to include Kepler as it performs worse than in OGL). Its on the release post.
https://community.bethesda.net/thread/54585?start=0&tstart=0
Pascal has some basic Async support, but they never bother to write the arch specific code for it, neither they bother to do a proper kepler code, even trought the focus of this patch was to improve perf on "old cards", as a result Kepler perf on vulkan is broken.
But for using Shaders Intrinsic Funtions, via GCN-only Vulkan extensions there is time.
Anyway, i rather AMD to lead DX12 perf for a gen or two, than see a AMD vs Nvidia title fight, its not gona be fun to be on either side if that happens.
Kepler + Async...
So many lols.....