It already does, in the T2. It seems to me like future T* chips will run more and more of the system, leaving the x86 to become something like the MBP’s discret

It already does, in the T2. It seems to me like future T* chips will run more and more of the system, leaving the x86 to become something like the MBP’s discrete GPU option. And then, like discrete GPUs, eventually an x86 CPU is only available in top-end models.