The motoboot.img in the 4.4.2 non-GPE stock ROM and the GPE stock ROM (ie the 'official' motorola leaked ROMS) are the same.
I ran a binary diff on the motobot.img files.
This means the bootloader for non-GPE and GPE are exactly the same. Thats assuming the leaked ROMS actually are the real official Motorola ROMS and non-one has fiddled with motoboot.img before they have been uploaded.
Therefore the process of unlocking will be the same I suspect, I dont see how it can be any different, ie GPE phones need a code to unlock them.
So even if you flash motoboot.img from GPE to non-GPE (ie basically reflash the SAME bootloader) the bootloader will either:
a) need unlocking again via code (if reflashing motoboot.img locks it)
b) stay unlocked.
Either way the phone knows it has at one time been unlocked due to blown fuses or whatever method is used.
I suspect it stays unlocked but maybe someone can confirm.
What you cant do is flash GPE bootloader and expect it to work like a Nexus bootloader, because as I said, its the same as the non-GPE bootloader. Now Im waiting for someone to prove me wrong