We noticed that too this evening.
Side comment, we'd like to be able to change that add-on domains settings show as mail.thatdomain.com instead of the primary name as that's how cPanel gives the settings but also, if customers ever split a domain off to their another account and end up on a different mail server, they'll need to change the details if they used the primary name but not if they use the actual domain they're looking at.
