I think this is a result of the strategy that the AI chose for picking languages. I saw when it was planning what to do it said that it was going to use a regex against the post titles. Probably it only included the specific languages above in that regex. Leaving some languages out. Which should still mean it hopefully has accurate numbers for the languages it chose to look for, but it might be missing several other more or less widely mentioned languages.
If I ask it specifically to count how many Show HN posts mention Lisp or Scheme in the title, it says there’s a total of 370 mentioning one or the other of those.
I asked the chat tool to count how many times each different programming language is mentioned in different “Show HN” post titles.
If the tool is accurate, it seems that the results diverge somewhat from what you are implying.