(author here)
Me neither! Don't know how or why it suddenly appeared on the HN main :)
Just to provide a bit of the personal context: this article caused creator of DaRu (Sameer Deshmukh) to contact me and propose to work on DaRu together, and so I did (see @zverok here: https://github.com/SciRuby/daru/graphs/contributors). I also was, for some time, SciRuby/DaRu's mentor for Google Summer of Code (and, IIRC, it was my initial idea that daru-view grew from).
Also, since that article, an independent dataframe library https://github.com/ankane/rover was created by Andrew Kane, handling some of API and implementation in a cleaner way.
That being said, I am not sure that DaRu, or Rover (or "dataframe" idea in general) has enough visibility in the Ruby community. It is mostly thought as "some special scientific thing", while I believe in 2021 it should be seen as one of the necessary everyday high-level datatypes.
That's what I'd focus this article on if I'd written it today.