That just doesn't seem like a fair standard. Why should only experts in a relevant field talk about the coronavirus? Nobody tries to stop people from sharing hospital stories from their friend's cousin's boyfriend who's a nurse.
But SEOd medium posts have different reach potential than a facebook comment/phone call with friends/family. That's kind of the whole point of them.
Now, if a total non-expert had come out of nowhere with an analysis that contradicted the public health establishment, definitively showed that the danger was massively overblown, and was right, that would be one thing. But this medium post was incorrect in its conclusion, quite confident in its conclusion, and advised courses of action that would put many people in danger (such as reopening schools).
I'm also not sure that distinguishes the case I mentioned. It might also cause problems to assume some particular anecdote is true and representative.