By default they are actually called Personal Messages rather than Private Messages (because admins can see them).
This seems like an important concern if it isnāt made clear in the TOS that messages can be read by administrators/moderators, which isnāt the default for old systems like the post office which isnāt supposed to read peopleās letters and they arenāt able to anyway unless they break a letter seal.
There is an alert banner option for the A.I. message system that alerts users that those messages can be monitored by moderators, may be a good feature for that to be an option for regular personal message topics also.
Havenāt tried that but would guess there would be some complaints. Way to respond to that could be to recommend alternative means of communication outside of discourse.
I turned off chat but kept personal messagesāPMs are easier to manage and keep stuff organized, while chats felt a bit too instant and messy for longer or more thoughtful convos.