The expectations seem to have moved to RimWorld/Data/Core/Defs/Misc/ExpectationDefs/Expectations.xml . I tried updating the wiki, but in the preview, it didn't render the file. I don't know the mechanics of the file-rendering.
The section "Situation General" still contains a comment about it, indicating that the expectations might have previously been there. I think it would be nice to have a separate article on expecations, though, since it is quite a central concept.