I specifically covered that. If anyone other than the original sender (one end of the communication channel) and the intended recipient(s) (the other end of the channel) is granted access to any information about the content of the messages (including not just the full plaintext but also e.g. a digest created by a neural network on behalf of the service provider) then the system does not have the characteristics of end-to-end encryption. You've only encrypted part of the communications channel.

In any case, advocating for mandatory digital spies on end-users' devices is arguably worse than attempting to undermine E2EE.