First, tihs document is about HW Certification. You can ship an ARM-based system that doesn't follow these rules, just won't be certified by MS -- much like many Android devices aren't Google certified.
Furthermore, MS actually bent over backwards on x86 and required for certification that the option to disable secure boot be provided (they could have been silent on this issue):
"Enable/Disable Secure Boot. On non-ARM systems, it is required to implement the ability to disable Secure Boot via firmware setup. A physically present user must be allowed to disable Secure Boot via firmware setup without possession of PKpriv."
I'd wait for MS's response on ARM. They've taken some interesting architectural approaches with their current ARM implementation (striped and actually secure SD cards). There may be architectural reasons for this. Or it could be that there are security issues with it, given that UEFI on ARM is pretty new.
But in any case, if this is important to an OEM they can simply not get HW certification. This doesn't block anyone from actually installing Windows 8 on ARM on machines w/o this capability.
It appears that ARM devices can fallover to legacy BIOS mode to support non UEFI OS's.
From page 109 of windows8-hardware-cert-requirements-system.pdf:
System.Fundamentals.Firmware.UEFIDefaultBoot
Target Feature: System.Fundamentals.Firmware
Title: All client systems must be able to boot into UEFI
boot mode and attempt to boot into this
mode by default
Applicable OS Versions:
Windows 8 Client x86
Windows 8 Client x64
Windows 8 Client ARM
Windows 8 Server x64
Windows Server 2008 Release 2 x64
Description:
The System firmware must be able to achieve UEFI mode
boot by default. Such a system may also
support fallback to legacy BIOS mode boot for deploying
OS images which do not support UEFI, if the
user explicitly selects that option in the pre-boot UEFI BIOS menu.
This requirement is If Implemented for Server systems and applies
only if a Server system is UEFI capable.
Agreed on rest of the points, but Windows 8 on ARM is more like Windows Phone in the sense that you can't ship an ARM based system like you can with x86. You need a special license, there will be no OEM or user installable versions of Windows 8 ARM.
Based on this you could make a case about this being an antitrust violation as they are tying one product (which is a monopoly in one arena) to another product in an arena which isn't a monopoly.
Furthermore, MS actually bent over backwards on x86 and required for certification that the option to disable secure boot be provided (they could have been silent on this issue):
"Enable/Disable Secure Boot. On non-ARM systems, it is required to implement the ability to disable Secure Boot via firmware setup. A physically present user must be allowed to disable Secure Boot via firmware setup without possession of PKpriv."
I'd wait for MS's response on ARM. They've taken some interesting architectural approaches with their current ARM implementation (striped and actually secure SD cards). There may be architectural reasons for this. Or it could be that there are security issues with it, given that UEFI on ARM is pretty new.
But in any case, if this is important to an OEM they can simply not get HW certification. This doesn't block anyone from actually installing Windows 8 on ARM on machines w/o this capability.