That's basically what they did when they made the switch from PPC to x86. IIRC, there was an edict a few years before the switch (Jobs talked about it in an in

That's basically what they did when they made the switch from PPC to x86. IIRC, there was an edict a few years before the switch (Jobs talked about it in an interview at the time) where teams were told something along the lines of not making any design/optimization decisions that were tied to PPC. They likely did the same thing with x86 this time.