They have all the pieces already. OSX already runs on ARM and can handle apps that support multiple architectures and the Apple 9X is more than fine for 90% of their user base.
The only problem is around Carbon. I can't imagine them investing the effort into porting it to ARM and it has been deprecated for a while. But still some people would lose the ability to run some existing apps.
It always seemed like the hyper-scale vendors' roadmap had to include "And when Intel reaches the end of process scaling, switch to lower-cost commodity vendor CPU" at some point in the future.
ARM x86 partnerships are one source. But resurrecting and improving other ISAs is another.
Of course, this reorg may be Intel putting all their chips into the data center basket to ensure they're always more competitive. Because, hats off to everyone there, they can work chip magic when they have to.
Tim Cook has already said iPad is the future of PC. We may as well move to the iPad ecosystem. For content creation let it stay on the x86 and macOS, and if Apple wanted to do some cost saving they now finally have an option, AMD. I bet Zen CPU will be more then enough for Apple needs.
I'm going on a limb here, but nowadays, 60% of macbooks (mainly the pro) are used for software development and 30% for creative work (video and editing). While something like half of those professional applications would be fine with the 9X, the other half would be left hanging for a better machine.
However, if they want to make the switch in the near future, I think that the new MacBook will first be released with an ARM processor. This way they won't alienate their core market and they will have a testing ground. Then, I'd predict two or three generations until the pros catch up.
> The only problem is around Carbon
They have the money, if they want to change to ARM it won't be Carbon stopping them.
Your numbers are way out on a limb.
In a single year, Apple sells more Macs than there even are software developers in the world.
College students alone form a much bigger market than software developers.