What you're saying is that, technical details aside, Windows 10 Enterprise certification effectively requires the ability to install alternative OSes.
Is that also true for non-Enterprise certification? Because the (dated) article implies otherwise. And it remains a fact that the Surface RT line was locked down so no-one could install an alternate OS on it without MS's permission. I don't know how much clearer MS could make their ambitions for control.
Yes, as there's no distinction for enterprise vs. non-enterprise certification. All systems that pass Windows logo certification have to be able to disable Secure Boot AND load user provided keys.[0]
If I had to guess, Microsoft locked down the Surface RT and wondered if they could get away with it, then once there was backlash and they realized that high-security environments wouldn't like it, they never spread the requirement to x86. That or antitrust fears.
Is that also true for non-Enterprise certification? Because the (dated) article implies otherwise. And it remains a fact that the Surface RT line was locked down so no-one could install an alternate OS on it without MS's permission. I don't know how much clearer MS could make their ambitions for control.