The platters used to be coated with iron oxide as the magnetic coating.

Modern ones use more exotic materials.

Yes but that was like 40 years ago. I think by now the phraseology should reflect reality after about forty years.

We still talk about "bugs" (99+% of computer defects in the past 70+ years have not been caused by insects) and "AJAX" (long after most of these requests use JSON instead of XML).

How many horsepower does your car have?

Ironically, I only started hearing the term being used in the past decade, as a colloquial alternative to solid-state storage.

“Phraseology” is subtly different.

You mean “vocabulary”, “terminology”, possibly “nomenclature”.