It does mean you probably shouldn't listen to them, because the expected value of listening to them is negative.

It means I shouldn't listen to them in general. The LessWrongers are mainly wrong about things they think they understand: when they aren't overconfident, their improvisational skills tend to be decent. They were an excellent source of information about COVID-19, but they're a terrible source of information in the areas where they think they have expertise.

When there's a crisis, it's still worth checking in to see what the LessWrongers are saying about it, because it might be very useful, and it's pretty easy to tell: you just check whether it looks like they're doing science, or Rationalism™®, and only investigate further in the rare cases where it's the former.