Please, let's not get us distracted by a discussion, if this is a privacy leak or not (this might be a matter of definition).
May I explain my scenario?
I work for a company where all relevant emails are collected in what we call a "sales inbox". I tend to forget to include this mailbox address in the Bcc: field, so I set it up in "Account Settings > [Account} > Copies & Folders > Bcc these email addresses:" as described. If the email should not go into the sales inbox, I simply delete the address from the Bcc: field.
When I receive an invitation and accept it, this acceptance mail is sent to the sales inbox. I don't have any control, if it is sent or not. I don't want to send all accepted invitations to the sales inbox where everybody can read it.
Since I cannot delete the Bcc: from the acceptance mail, I considered in a privacy leak. Perhaps there is a better word for it?