This doesn't address the parent's excellent question: how do these models continually get trained and updated if they put their key sources of training data out of business?
Related: I'd be quite worried if I was a Q/A site like StackOverflow or Quora.
Imho, quora users don’t use it for finding answers but rather reading personal experience. I used to write on quora fairly often many year ago. But something happened, and in my subjective experience the platform became far less interesting and useful. Significant part of questions turned into barely hidden shills for business or products, right answers seldom ever get visible and overall quality of content went down drastically. Maybe I’m not a representative but from my point if view the readers and writers on quora 2023 won’t have any different experience when there’s some smart machines that gives right answers.
It's not excellent. It's a red herring. Google is already showing responses on the SERP without you having to go to SO, without AI, and the hypothetical scenario hasn't happened.
Related: I'd be quite worried if I was a Q/A site like StackOverflow or Quora.