No, that is incorrect. It has nothing to do with the size of the sample.
"Anecdotal evidence is evidence from anecdotes: evidence collected in a casual or informal manner and relying heavily or entirely on personal testimony."
https://en.wikipedia.org/wiki/Anecdotal_evidence
"Anecdotal" also means data that is not verifiable. In this case, the data is verifiable even if the news spread via Facebook.
> trying to extrapolate from a narrow sample to draw a broad conclusion. [...] You've moved the goalposts to say that if it kills even one young person then young people are generally at risk.
I did not draw a broad conclusion, I stated clearly in this thread that this is one sample, and old people are at much higher risk. So did the article. You are constructing a straw man argument that doesn't accurately reflect or counter my point of view.