How is this supposed to work in reality? Do we really want to provide Meta, Apple and Google with a list of phone numbers of accounts of militarly and security personell in order to have their feature-flags for sharing links/photos enabled?
Not saying it’s a perfect solution, but they might consider it a “95% good enough” solution.
Unless by 'feature' you mean the mandatory scanning?
Their tower dumps contain enough metadata to determine all the people who spend most workdays at office buildings in McLean Virginia. And then, of course, where those people sleep (i.e. charge their phones) at night. It takes positive effort to erase that data, and believe me, it's being erased. The powerful people don't want it to exist.
So yeah, there is already a system for doing this kind of thing. It will be extended. Plebs like you and me don't get to use it.
Good on those powerful people then, because this data should not exist.