Years ago we looked to emulate on x86, but with the rise of ARMy, billions per year versus a couple hundred million x86 guess which gets attention.
And we now have 10nm cores ramping at TSMC and Samsung and 7nm shortly after it is no wonder everyone has moved to ARM.
Even intel doing lip service if their 10nm arrives at all!
Emulation is first step to full native optimization which is happening at Apple and every other application, the ARMy can't be denied with billions upon billions served
http://www.fudzilla.com/news/42189-microsoft-plans-to-bring-x86-emulation-to-arm