Maybe it does explain why we're surprised about a personal friend winning the lottery - if we identify the "well-supported model" we were relying on.

Note, it need not be a model which is well-supported in terms of epistemic rationality. Merely that the model has been instrumentally useful: i.e. "my personal friend won't become incredibly wealthy without warning."

Alternatively, maybe it is worth considering different types of surprise which have some things in common but some differences.