If AMD pulled their finder out and actually went to Apple to sell the technology Apple would give AMD a pile of cash for exclusive IP rights and drop Intel from all their systems virtually overnight.
Intel only put these huge iGPU's on their chips because Apple said "your CPU's are fine but AMD's iGPU's are much better"
AMD are useless at that ^^^
Or maybe they have, maybe in a years time everything Apple will have HSA enabled Zen chips in them.
That could certainly happen, although the volume needed for it would certainly be very high; and Zen needs to be a success before it could happen as well. Not just comparative to Intel's current line up as well, but better; or at least use less power for similar performance.
When the 2013 Mac Pro launched the 6 core variant with two AMD FirePro D700's cost less than buying two desktop FirePro W9000's and they were essentially the same chips. So AMD are selling at silly low prices.
If Polaris and Zen are winners I could clearly see Apple taking a massive interest, but only if AMD can also supply the volume needed.
It would be amazing seen an all AMD HSA laptop or desktop from them though.