I'd argue that current events have a direct impact on all of us and this absolutely warrants discussion. Furthermore, I'm not sure I know of any instance where a President has disseminated writing like this. It's an interesting change, since it means that former Presidents can continue exerting influence.
I actually agree with you, but given that the article was posted by mwseibel, I wanted to see what everyone's thinking was. Just because he's a significant YC partner doesn't mean he knows/has authority over HN. It's a valid discussion to have.
But what's the appropriate line? A hard line with no room for interpretation, even in significant events? Where does Coronavirus land in that then? It certainly affects tech/hacking, but it definitely is being tainted by politics and belief structures. Are the only valid articles ones that talk about remote work?
Similar thing related to civic action. Keeping politics out of HN is a good rule, but man, that line is never going to be discrete.