...to someone else, you do not even know in real life.

just for fun, i researched this. Looked at the Office of the Privacy Commissioner of Canada, and the British Columbia Privacy Act. From what I can tell anyway… “a takedown request aimed at suppressing someone else’s posts has a plausible public-interest / transparency angle. So if the app creator simply posted, “Here is the takedown request we received from John Smith, there is no reasonable expectation of privacy.” in other words, if youre going to send legally threatening letters to app creators on a notable non-censorship protocol, dont be surprised when the email is published in its entirety.

I might be wrong, but I did not perceive this as him threatening you in any way. In true German fashion, he did what his attorney told him to, asking you to preserve the data of these incidents, surely for legal action against the mentioned user. Doing this requires him to put his real name there otherwise ist won't be accepted. Is this a questionable ask towards an uncensored protocol that gives no guarantees for data persistence? Hell yes. Telling him to fuck off if you don't want to get involved is perfectly fine, imo. But you do not doy people with their real names, ever. Just my 2 Sats ofc.

Just for clarity. I guess this lawyer did not use any form of encryption to protect the content of the message?

Exactly.

Yo, the relay is public he can preserve the events himself. He doesn't need the relay runner to do it. Also, he doxxed himself by sending an email to an untrusted party from his own name.