Unless we're positing a singularity, I don't think the public's demand for better treatment is remotely close to satiation point, or that computerised efficiency and accuracy will reduce the demand for nice, qualified middle-class people to explain what the computer is recommending for them. That's even before we've started considering whole new classes of middle class job that mass adoption of technologies like gene sequencing could entail, or the largely-justifiable layers of regulation and respect that give medical professionals a lot more power to keep their jobs relevant than the average union member

I don't think "surplus of trained doctors" is a real problem I'm likely to see in my lifetime, never mind a likely consequence of the foreseeable future improvements in medical data collection and diagnosis.