alt Hacker NewsIf google allows that for pixels, I don't see why Motorola wouldn't.
Besides, GrapheneOS would probably don't want to get into a situation where their keys are burnt into hardware non-modifiable. They had to revoke such a key once in order to protect their users (against an attempt to hijack the project).
Providing an unlockable bootloader with all of the security features intact for alternate operating systems is part of our hardware requirements. Our main requirements are listed at https://grapheneos.org/faq#future-devices which covers both updates and hardware security features.