I’ve read a few of his other entries from when they were shared here. It’s interesting that someone can have such a different baseline view on reality than I (for example, the opening statement that humanity will just end itself in a couple centuries) but the posts are enjoyable nonetheless.

I imagine he's referring to the Doomsday Argument (https://en.wikipedia.org/wiki/Doomsday_argument). It's popular in certain circles but controversial.

His magnificent 'Dragon Speech' also made it clear that he'd already lost some of his marbles:

https://www.youtube.com/watch?v=CBrj4S24074