I think the important point is that Secure Boot flips the default.
We always expect manufacturers to "do nothing" if they can get away with it. Pre-Secure Boot, doing nothing meant you could install whatever OS you wanted (subject to other hardware limitations, of course). Post-Secure Boot it will mean that you probably can't (even if there's a mandated escape hatch, how well will it be tested? And so on).
We always expect manufacturers to "do nothing" if they can get away with it. Pre-Secure Boot, doing nothing meant you could install whatever OS you wanted (subject to other hardware limitations, of course). Post-Secure Boot it will mean that you probably can't (even if there's a mandated escape hatch, how well will it be tested? And so on).