I hadn't connected that to a pandemic-induced demand increase, but that could well be true.
As for submissions (rather than comments), it does feel like HN has shifted more towards broader industry and politics news, rather than just tech and programming. I'm okay with this, in fact HN has displaced Reddit for me thanks to the much higher standard of discourse, although I do worry a bit about marginalizing the crunchy tech content for those who come here for that.
I think the guidelines might be right, in that this hasn't really seemed to change in the ~10 years I've been here.