The thought experiment did not originate with Einstein. The name gedankenexperiment predates him and Maxwell's use of the concept. So the article also misreports the origination with Maxwell. Maybe they should have skipped the couching in history if they didn't know the history or even want to look it up.

And now that I'm reading the article's comments, other readers have also made those points.

This article is useful as a tackle dummy for skeptics but not much else.