It means nothing, it’s just a paycheck you sign and then you get to say “I certify my OS is Unix”. The little bit more technical part is POSIX compliance but modern OSs are such massive and complex beasts today that those compliances are tiny parts and very slowly but very surely becoming irrelevant over time.
Apple made OSX Unix certified because it was cheap and it got them off the hook from a lawsuit. That’s it.
Most likely, as with all AI as a service startups. After a certain mass of users the models can’t keep up. So to reduce the response times they pay offshore firms to have real people answer the chat. Unfortunately, doctors willing to answer a chat all day are way less numerous than cheap labor.