> Something suspiciously absent from this article is addressing whether some of these are in fact human visitors, but humans issuing chatgpt or similar queries instead of going directly.

That's not absent from the article, it's right there in the section titled "The Claude ratio". ChatGPT, Claude, etc. use different user-agents for scraping vs user-initiated requests, and the author notes that user-initiated requests were an absolutely miniscule fraction of the total traffic.