I think the key difference (hopefully) will be that there are a limited number of hardware configurations for Mac. Still a lot (i.e. 100+ SKUs) but not nearly the number of x86 hardware configurations (i.e 10000+)
Also presumably if Apple wants this to happen, they as a single vendor can provide a single definitive answer on what they are doing for each configuration. Eventually...
In the x86 world, there is Intel, AMD and like 50 different manufacturers each with a particular HW implementation/BIOS customization, leading to IntelAMDHardware_Vendor_customizations^50 permutations that'd need to be validated.
Also presumably if Apple wants this to happen, they as a single vendor can provide a single definitive answer on what they are doing for each configuration. Eventually...
In the x86 world, there is Intel, AMD and like 50 different manufacturers each with a particular HW implementation/BIOS customization, leading to IntelAMDHardware_Vendor_customizations^50 permutations that'd need to be validated.