Re: I agree, I would rather have FDT than UEFI
Locked UEFI presents a *problem* -- not for users, but for the Great Monopolist of Redmond. When they announced that ARM systems *must* have a locked bootloader in order to support Windows for ARM, they were thinking about consumer devices. They didn't want people rooting their Windows devices and installing Linux (Android or otherwise).
Fast forward to servers, however, and this becomes a problem. If there's going to be an ARM Server market, Microsoft wants a piece of the software action. However, in the 21st century, no server vendor in their right mind would lock out Linux. This will be even *more* true on ARM, where the ultra-portability of Linux is expected to give it an even bigger market share than it has on Intel.
And of course, no server vendor is going to say "you can only use the Linux distribution that came with the system" (ok, Oracle might, but they don't count). They know that reloads are normal.
So no, I don't think we're going to see locked UEFI on ARM servers, and if Microsoft wants a piece of that market, they're going to have to change their policy or be left out.