alt Hacker News> First, it reverses the problem. Services should be sending an age-appropriateness (or even just general content classification) signal to the device for local processing, not the other way around.
OK, so say the device receives a signal that say that an app is not appropriate for children under 13. How would the device find out if the user trying to run the app is under 13?
The question itself (ie if the user is under 13) doesn't matter. Already for the current legislation there's nothing stopping the device owner from intentionally lying about the age. So really this entire exercise is about providing a standardized means of control over filtering, thus my observation that the proposed measure is both backwards and overly limited in scope.
The software on the device can do whatever it would like with the signal it receives, including consulting the user account metadata for declared age if the device owner so desires.