A plan B that targets the consequences of an advanced AI specifically is more problematic because, if the people who are all excited here see their fantasies come true, then not only are we all screwed, but the hardship will be permanent. I haven't yet worked out how to develop a contingency for that.
And look at all the comments on this very article replying to people who are positing contingency plans: it's almost all ridicule and telling them that their efforts are pointless. So, apparently, lots of people are upset at the very notion that people are considering contingency plans.
More than a fund, an alternative.passive income source(s) is another factor. Given the situation now, it makes sense to ramp these side sources up and get them closer to mainline viability.
I agree there's a huge amount of uncertainty. But I think there still must be some sort of plan B. Maybe a sort of nest egg of sorts of what to do in case it all goes to shit.