Yes. That's what I thought and that, as much as anything else, gets my goat. I understand that TPTB were probably not allowed to say why, but the "reasoning" for removing it seemed specious to me.
Whilst it is fair to say that Ars (including comments and forums) has been scraped forever, this emerging capability will allow some pretty scarey inferences to be made about posters. I often wondered what could be gleaned about someone with, say, 10k posts, if they could all be inspected as a corpus. Well, I guess we are about to find out.
I don't like the rise of the machine LLM, but I am much more concerned with people deanonymised for profit. Consider those posting in the ADHD thread suddenly being denied health insurance or those admitting to liking a good drink not being able to get vehicle insurance.
I'll bet an LLM could deanonymise most people who post here in a heartbeat. I have always been circumspect about what I post online (and it's pretty much only on Ars). Now? Meh. I think I'm out. It's not worth the risk.