Apple's MO with every _smaller_ supplier has been:
1. Set up office down the road 2. Poach top engineers 3. Come up with some excuse to cancel use of supplier and integrate in house.
The media and fanboys are remarkably complicit, coming up with excuses for apple's behaviour and giving very favourable coverage.
In this case, intel are too big for this trick to work and apple already have loads of ARM talent so it makes perfect sense to transition.
I wouldn't rule out apple trying on the whole 'we don't need a license' thing any more with Nvidia but it's probably unlikely given their size.
I worked at imagination technologies who was bankrupted by Apple doing this technique and whose GPUs are still used by them so I saw this and people's remarkable lack of attention on the incredibly consistent pattern of control first hand.
While all of this is obviously true, I actually think it's great that intel and AMD are receiving some serious ISA competition and it will net benefit non-apple consumers too long run.
Congrats to apple for pretty impressive technical work but I do wish more would see apple for the ruthless control freaks they are.
At the end of the day I think rather mundanely it's really more about money than anything else.