If it is due to blatantly obvious handicaps, that's a different story. But good luck proving you we're passed over because the employer figured out you have headaches.
In my view, there's a pretty bright line between the described business and today's background check companies.
>So this hypothetical Narrative Data company would have a largely-illegal business plan, and nobody would notice?
Imagine a meeting with HR. Company is racist. They never really made it into an official police of course but just by joking or sort of non verbal communication they figure out that other higher ups hate certain races. They will talk about so and so's personality "not matching".
It is fairly easy for them to figure out an euphemism used to signal this or that other person needs to be let go because their race isn't "right". Let's call it "personality reasons" or say "restructuring reason". It doesn't matter as long as it never officially put into writing.
It would be an uphill battle to successfully sue for discrimination. One would need to compile historical data and show that people of a particular race have been consistently not hired or laid off once hired.