Once unlocked, your device loses warranty (already expired anyway) and some apps (e.g., banking, Netflix) may refuse to run unless you hide root. Also, you cannot relock the bootloader without an official code, which is now impossible to get. Relocking with an unofficial method may brick the device.
adb shell su
By default, the advanced settings needed for unlocking are hidden. You must enable them. How to Unlock Bootloader in HONOR 6 Plus phone
Some GitHub projects offer scripts to bruteforce the 16-digit code based on your IMEI, though this is time-consuming and technically difficult. Step 2: Boot into Fastboot Mode Once unlocked, your device loses warranty (already expired