Someone has never dealt with HIPAA laws and it shows.

Who out there is going to be feeding patient medical data to Mythos/Fable?

Whoever Anthropic can convince, to help them form a competitor to OpenEvidence, who already feed patient medical data into their systems.

...the same groups who are currently feeding it to Sonnet and Opus?

Well, they won't be feeding it to Fable unless Anthropic can provide a signed BAA.