Just to clarify, this "on device content control" defies all the benefits of the E2E encryption because it is "at the end". It will enable Apple to implement E2E and give the authorities a channel to program the devices to report users in possession of content deemed unacceptable by the authorities.
The are speculations about this being Apple’s solution to government demands so that they can continue migrating to E2E.
They are trying a solution where the device reports you to the authorities so that Apple gets out of the business of knowing your data.