What part do you see regulations (data privacy/ HIPPA) playing in all of this? Even if the relay has no "access" to the data, the responsibility of record security has shifted from hospital to the relays (more vectors to attack). In the name of the "peoples protectoooooors", govts likely to fight back against this. A hurdle but not insurmountable.
Patients (in the US) have a right to request their data. Once they have it, it's theirs to do as they please. But the #medpleb movement would require the people to get off their ass and actually get them.