I received a number of these, too, and I know exactly who the user is. (The "Optout" name shows up in my list of the top CO's whose hides I've found so it was easy to identify her.) I know she is still active...very much so, in fact. I'll ask her if she's done anything to her profile lately that would have caused this.
Update to my earlier message: My friend said she had "selected to opt out of third party vendors" on geocaching.com. To me this makes sense (and I'm really nobody so take this with a grain of salt!), but in essence Project-GC has no idea who my friend is at this point. Her favorite point is "removed" on Project-GC (and is assigned the "OPTOUT" user name), but the total on geocaching.com remains the same. In order to reconcile the difference, Project-GC is adding one back in on their end. Again...this makes sense to me, but since I don't work for P-GC I'm not sure if this is the actual case or not.