While technically IRCops (not channel ops, unless they also have IRCops) might be able to review private messages (ie: queries), realistically it's not something many are willing to do, since they usually have other more important things to handle. If you're worried about a privacy aspect, it's never recommended that you send private information, ie: credit card numbers, phone card numbers, social security/social insurance information, etc. via an unsecure access.
IRC chat (whether via pm/query or in a channel/room) is classified as unsecure for this type of information.