[thegrim22]

From the study the article is about: "participants who had recovered from Covid-19 in whom symptoms had resolved in less than 4 weeks or at least 12 weeks had similar small deficits in global cognition as compared with those in the no–Covid-19 group".

So no, it doesn't apply to everyone that has ever caught covid. It's only (allegedly) people who had multiple months of "symptoms" post-covid that had a change in cognitive ability.