I also can't help but note that this blog post itself seems (first to my own intuition and heuristics, but also to both Pangram and GPTZero) to be clearly LLM-generated text.

I hate to be overly simplistic, but:

NIST doesn't seem to have a financial interest in these models.

The author of this blog post does.

This dichotomy seems to drive most of the "debate" around LLMs.