K8y
I already answered the question that there is almost no need for a backdoor, but if we go further,
since there is no verified boot, and the devices they run on (except Pixels) treat any custom OS as just
a piece of partition on the device, there is nothing that theoretically stops them from signing and providing
malicious updates if the French government forces them to. They can even sign it with their own keys and
distribute it to specific users, based on IP or country, but not limited to. That modification does not have to
go to Github, it can be silent, signed malicious update sent to the update servers, where the web-server
will direct all "normal" users to the original "clean" update, and the targeted users to the malicious one.