I wonder if there's a longer term strategy to start migrating devices like the MacBook Air over to their A-series CPUs, instead of Intel.
They have undoubtedly got internal prototypes of a MacBook Air running OS X on their own processors. And their development toolchain and libraries are merging iOS and OS X more and more every year. This year, there were a couple of WWDC talks specifically about sharing code between the two platforms.
I think it's fairly obvious that the technology stack is ready both on the software and hardware side. It's just switching architectures isn't just about whether you can, it's about when the best time is to maximise chances of success. When they moved to Intel, they could supply an emulation layer to run older applications. That won't work as well this time around because it will be a lot slower. So they will need to push developers hard to port their software, and their best tool for doing that - the Mac App Store - isn't a huge success.
One thing they've been doing in their latest hardware designs is supplying two chips that are used in different circumstances. Surfing the web? Use the low power GPU. Playing a game? Switch to the high power GPU. Need to detect orientation? Use the low power accelerometer. Need accurate movement information? Use the high power accelerometer.
They could conceivably do this with their laptops. Ship an Intel co-processor for running things like Photoshop that haven't been ported, and switch it off when you're only running ARM64-only applications for better battery life. It would raise manufacturing costs, but it would ease the transition and Apple might be willing to take the hit on it for that reason. And they just added a feature to point out applications that hog battery to the end user last year. They are making this visible for a reason.
Aside from their computer lineup, the other piece of the puzzle is Apple TV. They've already got the makings of a very successful games console. They have a set-top box running iOS, CPUs and GPUs that can handle good quality games, dedicated controllers, a large games library, and an online distribution channel. Their current hardware is underpowered, but drop an iPad Air 2's internals into an Apple TV box and they'd have a very successful console.