I updated an opportunity's Close Date from the previous quarter to the current quarter, but I can't see it in any of the buckets within the Waterfall module. Based on the change I made to the Close Date value, I would expect this to be in both the 'Pulled In' and 'Lost' buckets. Why is this?

This is the expected behaviour, as we intentionally do not show opportunities which qualify for both the 'Pulled In' and 'Lost' buckets. The reasoning behind this logic is to solve the immediate pain of inflated 'Pulled In' and 'Lost' bucket amounts by automatically hiding deals that match both categories, as we do not expect Closed Lost opportunities being pulled into a future quarter to be a standard use case.