People have been doing "authorized unlocks" of their bootloader, where they ask for permission to unlock the bootloader and in exchange their device is marked as such by Google. Until now, being marked as unlocked didn't have much consequence, so power users were content to take this route. I predict this will change.
Used to be we would rewrite our bootloaders with hacks and exploits, authorization be damned. If I hack my bootloader without permission and then tell the device to imitate a good citizen, how could they tell the difference?