Recently, I got in hot water, when something I supposedly told someone turned out to be confidential and I was pointed to as the source. I am usually quite circumspect. But, I don't remember what I didn't say.
Whether it be about promotion and tenure, or journal reviewers, or faculty meetings, or personal information--no matter how outrageous it might be--you'll have to swallow it, or send a note to a higher-up with your concerns. The problem is that the higher-up might well hold it against you, or may share that note with some other higher-up who is not happy with your expressed concern.
Most of the time, I do not much recall any details of stuff that was confidential. Of course, it is rarely so confidential as portrayed, since it is likely that others have already spread the information, often others who know they should keep it confidential and are in higher positions. (Confidential information is a currency, used by people to cement their relationship with others.)
Some universities and journals make it a policy of sharing letters of reference, reviews, and memos of administrative processes, often under the rule of open meeting laws. Others do not. From what I have been told, neither method assures better and more fair decisions.