Ah, mesh shaders. Cool stuff. AMD retroactively added them to their old GPUs in drivers. I think same goes for Intel's post-Ivybridge GPUs(I think send opcode can throw primitives into 3d pipeline, if you are interested, you can go read docs). I guess Nvidia can do something similar.
And even if they don't have such straightforward way of implementing them, they probably(my guess, can be wrong) can be emulated in geometry shaders.
What I don't like is apparent removal of vertex fetcher, but maybe there will be extension that will return it.