Interesting. I hadn't heard about this. I got this response from Xiaomi earlier today after complaining they mis-sold me a phone as their unique selling point was the ability to unlock the bootloader.
"We hope you could understand, that such an operation will disable some
of the built-in security features of the system, and those security
features are part of what keeps the operating system safe and your data
secure from exposure or corruption. And this misuse will void your
phone's warranty and it may render your phone useless depending on the
security measures in place on your phone."