A lot of our community technique goes into either (1) dealing with "beliefs" being an evolutionarily recent system, such that our "beliefs" often end up far screwier than our actual anticipations; or (2) trying to get our anticipations to align with more evidence-informed beliefs.

Wow. I hadn't heard this expressed quite like this before... We have one territory and two maps, and we can help get both maps in sync with reality by getting them both in sync with each other.

Is (2) related to taking ideas seriously?

To me there seems to be more going on here than in Belief in Belief where Yudkowsky encourages people to do (1) - to update vacuous or nonsensical professed beliefs. From Yudkowsky's article I didn't pick up that (2) needs to happen as well.