When I was shadowing, I had an orthopedic surgeon lecture me the entire length of a surgery about how he approached this particular surgery differently than a normal one, because he was working on a prison patient. He explained in great detail the disparities facing the prisoner while recovering from the surgery, how prison patients are at higher risk for post-op infection, how the surgery and recovery might affect how the patient interacted with the rest of the prison population, how it might make him a victim of violent crime due to being seen as a 'weakness' later on. He was concerned about the patient not getting the same level of post-op care that a non-incarcerated patient would get, and what kind of effect that might have later down the road. I'm not sure if he was taught any of this in medical school, or just observed through working with underserved populations for years and made adjustments as he went, but I was definitely impressed by him.
I do think there is a place to teach social disparities, especially because medical schools tend to be filled with priveledged students who have never seen them, but I think clinical opportunities, community service, etc. might be better than teaching them in a lecture hall. I do think it's the job of a doctor to educate their patient, work within the patient's limitations, and go the extra mile to make an insurance call, but I don't think that should be done to the exclusion of practicing medicine. That role could be filled by social workers. The role that the WSJ author is proposing should be filled by MPH graduates...that's why the MPH degree exists.