Truly private communication isn't a thing, as long as you use a platform (like the internet) you can still have your message to be seen.
Furthermore if people have nothing bad to hide what is the problem if the staff can see the PM?
I'd rather have problems be solved before something bad happen.
I don't have anything to say to this that hasn't been said to you already.
You seem to be trying your best to participate in the discussion for the sake of it but I want to remind you that you do not need to participate, specially if what you're gonna suggest is unproductive to the discussion (this is the second time in a row) and this time possibly harmful even. Remember it's okay to just watch from the sidelines. If you really feel the need to say something, please put some more thought into it.