When you create an app it is owned by the user that created it. When it gets published in the QMC it is still owned by the user that created it.
Once an App is truly in Production who should be the owner? Users come and go. So I don't think it makes sense to have the original user still be the owner.
I see that the Monitoring apps are actually owned by sa_repository.
As you don't have to be the owner to affect the app in the QMC (i.e. duplicate rename etc) it doesn't really matter if the owner is still around or not.