It would seem to me that eventually Apple will have some kind of 'identity proxy' that apps will need to talk to in order to have an app send to a real contact.

It would seem to me that eventually Apple will have some kind of 'identity proxy' that apps will need to talk to in order to have an app send to a real contact. It can be overridden explicitly when needed by the end user but the default would be a sort of unique UID that changes over time. Think private relay/URL's but for identity.