>It could happen, but from Apple's own announcements it seems like they were worried that the Mac was increasingly marginalized as a platform for AR/VR development, which Tim Cook constantly tells us (for AR at least...) is something he's super excited about for the future of computing.

Because it is. High end AR/VR is exclusively DirectX Wintel 64 based. There's pretty much no exception except for the toy implementation of things like Samsung Gear. Google abandoned Tango, and Daydream is on life support. Apple's ecosystem will remain irrelevant until they release their own hardware.