Naven
Answers
What does it mean when a service says there is no expectation of privacy?
That the operator can read what you send and is telling you so. It is an unusual thing to publish, and it is more honest than the alternative, which is a privacy policy vague enough to permit the same thing quietly.
Most services that can read your messages do not say it in those words. They describe encryption in transit, mention safety systems, and leave the reader to infer.
A service that states it plainly has given up the marketing advantage in exchange for not misleading anybody, and it lets you decide with the real facts.
Naven's terms say it because the screening requires it. Anybody who needs the operator not to be able to read their messages should use an end-to-end encrypted service.