Correct.
FWIW (disclaimer: I'm the developer of StopTheMadness Pro, mentioned in the article) I just ran two tests in Mac Safari, with StopTheMadness Pro enabled and disabled, and the results were exactly the same each time: "at least 18.06 bits of identifying information". Alas, that's a unique fingerprint, but apparently my extension doesn't make anything worse. If you look at the detailed results, the identifiers are things like User-Agent, screen size, time zone, and language.