Earlier quoted context omitted.
Those changes were all to more powerful processors such that emulating the old architecture wouldn't be that bad. In this instance, Apple would likely be going to a less powerful processors and thus emulation at any reasonable level of performance wouldn't be that viable.
ARM less powerful? Wait and see what Apple can do with their own ARM-design if they target Desktops / Laptops. We might get to see 32 or even 64 cores in a regular MBP. Now tell me how THAT would be less powerful than the current Intel offering.
If we had a MBP with 64 wimpy a53 cores it would still only have 50% of the performance of a Intel i7 8700k or AMD Ryzen 1800X on paper. Of course that is faster than most notebooks but if you truly care about CPU performance then you usually wouldn't use a notebook in the first place.