It’s not what they say happened, and I think people at openAI would not have answered like they did if it was the case. Grok finding answers that users got from open ai and recycling them seems plausible enough.

Years ago there were something a bit similar when bing was suspected of copying google results. Actually, yeah, sort of : the bing toolbar that some people installed on their browser was sending data to Microsoft, so they could identify better results and integrate them in bing.

Obviously some off these better results were from people with the bar that were searching on google.

Someone from google actually proved it was happening by setting up a nonsensical search and result in google, googling for it a bit with the toolbar on, and checking that the same result would then appear in bing.