In case it was not immediately obvious, this discussion is not about the Surface RT, but about the Windows Dev Kit 2023. It ships with a different Windows version, on a different Arm architecture, with different policies regarding locking down.
And? "In case it was not immediately obvious" by me specifically pointing an MS ARM device, MS's "policies" when shipping ARM devices have been much more locked down than x86. Around 50% of ARM devices released by MS so far have been completely locked down, incapable of running anything except for some version of Windows. Not just "FUD by nerd circles".
All ARM64 Windows devices have been "bootloader-unlocked". That has been the case for the last 5 years. Windows RT and Windows Phone devices are literally irrelevant to this discussion regardless of your anecdote.