Is the app age rating a warning?
https://www.bewebsmart.com/ipod-ipad-iphone/how-to-restrict-apps-by-rating/ 

If Parental Control restricts a certain age criteria, yes it can be a filter. There are filters like 9+, 13+ etc. If all apps are allowed by the admin, no warning will be seen on the basis of age restriction. It will be just metric to judge content of the app.