Solving the wrong problem
It's not chip feature/function that will make the difference for ARM. It's having a consistent and widely adopted* systems architecture so that software can run anywhere without extensive redesign (see for example the work Fujitsu had to do to get Lustre to be effective on its newest supercomputer).
And if ARM doesn't make that happen, maybe AWS will do so by default...
*Yes, there is an architecture. No, it's not widely adopted.