An unlocked bootloader is a treasured thing in the Android world. While many are happy to use their phone as it is out of the box and wait for manufacturers to provide them updates, there's a sizable crowd that loves the ability to install any software they want and get the latest Android version as soon as the community releases it, often months before the handset's manufacturer can roll it out. In fact, unlocked bootloaders are the key to keeping popular phones like the Samsung Galaxy S4 up to date long after they reach their official end of life. The HTC G1, for example, has an unofficial Android 6.0 Marshmallow ROM, as does the seemingly immortal HP Touchpad.
Sometimes, an unlocked bootloader is something that consumers and even carriers have to fight a manufacturer tooth and nail for, and may still lose. Other times, the manufacturer simply puts out an official unlocking tool and tells Android lovers and tinkerers to knock themselves out. That's exactly what ZTE has done, albeit with only a few select phones, and only in the US for now. Those phones are the recent flagship killer, the Daydream-ready ZTE Axon 7, and its predecessor, the ZTE Axon Pro. The official method isn't quite as simple as Motorola's, or even some unofficial methods for some devices. Users must register to participate in the ZTE community, then make an official request in the Developer's Lounge for their device to be unlocked.
Since the bootloader unlock just happened, eager Axon 7 and Axon Pro owners would be ill-advised to run headlong onto the site and get their unlock on. Not only is there practically no development for either phone right now as far as ROMs go, the Axon 7 doesn't even have a custom recovery available just yet. On top of that, as with most other methods of tinkering with your phone, your warranty will be rendered invalid upon unlocking. This means that your screen or charging port could suddenly give out with no outside stimulus a week from now, and you would have to either replace the part yourself, have it done, or buy a new phone. Either way, those interested can find out more by heading through the source link and putting in a request.