Skimming through the archive of the Ars piece, it's indeed much better written than the "ai slob garbage shit" standard I'm used to. I think I could adapt to detect this sort of thing to a limited extent, but it's pretty scarily authentic-looking and would not ordinarily trip my "ai;dr" instinct.
There is a ton of money to be made right now being an AI slop regurgitation - if you can take AI slop and rewrite it in your own words quickly, you can make a nice buck because it doesn't immediately trip the rAIdar everyone's built up.
It might not be AI-written at all. It might be written by a human with the research being done by AI.