[daxat_staglatz]

They have already done it, it is called the T* series chips.

The first version, T1, did the secure enclave thing, and controlled Touch ID, thermal and power management and a few other things.

The second version, the T2, added storage management, an image signal processor, an audio controller, and encryption for the SSD.

The next version will probably do even more things.

It seems to me that the most likely scenario is the T* chip being used for more and more things and the amd64 chip to be used for less and less things until the amd64 chip is more a "hardware acceleration" chip, like GPUs, here to handle specific tasks to be offloaded from the (now ARM) CPU.

The shift from amd64 as the _central_ processing unit to the T* chip does not need to be a clear cut (ditching the intel cpu directly and using the T* chip for everything) but can (and is) being done progressively (the T chips becoming more and more capable).