Oligarchic fits, and isn't mutually exclusive with being a capitalist. IMHO it seems like that's an inevitable outcome in capitalist economies if safeguards aren't instituted. Also I certainly don't think oligarchies are restricted to capitalist economies, either. It just seems like it would be the natural goal of amassing capital: rig the system in your favor.
Also I don't want you making up definitions, I just assumed you had another one in mind when trying to define what most modern corporations aren't.
Initially the CDC didn't know how much asymptomatic spread was going to be a factor: that definitely changes the math on advising everyone to mask up. By July of 2020 they were unequivocal: https://www.cdc.gov/media/releases/2020/p0714-americans-to-wear-masks.html