What probability for extinction do you consider to be low enough that it effectively becomes a Pascalian wager? Pascal was also writing about a single person's fate (AFAICT), whereas this is about the fate of everyone.

The point is that the probability doesn’t matter because the outcome, total human extinction, is given infinite weight.

Maybe Pascal argued that way for the human soul, but I don't think the AI risk argument needs infinite value to be at stake. Would you say that preparing for the risk of a solar flare or an asteroid impact is also a Pascalian wager?