The Ars comment section is very disappointing, with people conflating the harms of nicotine with tobacco. This is probably because of misinformation about EVALI ("popcorn lung") which was actually the result of a specific impurity in black market THC vapes, and has never been observed in a legitimate vape, nicotine or otherwise.
I think there's two separate incidents you might be getting mixed up.
Popcorn lung was a concern with diacetyl - butter flavoring - which causes popcorn lung in large quantities, like the factories where they make microwave popcorn. Not sure if it was just concern about it or actual confirmed cases, but it was removed from all ecigarettes a long time ago.
The actual cases of hospitalization with respiratory issues were from cutting THC vapes with vitamin E oil to make them appear thicker and higher quality. It was already well known that inhaling vitamin E oil vapor is incredibly bad for you, but the makers of those illicit vapes either didn't know or didn't care.
