I think if relays that don't want to deal with the regulations that come with medical data just blacklist that kind it should isolated them from that. Of course that assumes the courts and government act rationally so maybe a bad assumption.
Discussion
You should be able to host your own medical data, and allow your medical professionals to access it via your relay, but it would just be redundancy, if you can even find a someone to accept it, because they have their own compliance requirements.
Right so the relays that want to take that risk and liability would allow that kind other relays would not. Isolating themselves from compliance issues