You will get this message for Medicals (you do not need a medical exam) when any of the applicants medical report has been passed and expired, in that case they will extend the expiry date of your medicals to a later date. When doing so, it turns to be getting this message on portal.
I have the same message. Mine is March 10 AOR and my medicals passed on Apr 17th and after a month or so, I got a ghost update and my medical results turns back to "You do not need a medical exam". When I called CIC, they told this information that my spouse medicals has been passed but expired and they extended the medicals validity till Feb 2020. So I believe nothing to worry with this message.