I think that going broody is being confused with a laying cycle here. If a hen decides to set her eggs, she will stop laying until some time after she is taken off of the nest, but this is not the thing as a laying cycle. You are absolutely correct to associate the molt with the end of a cycle. The molt takes a lot of energy, so they don't really have much left for egg laying. after the first molt, the hen will resume laying, but normally they never lay as well as they did before the first molt, in their "pullet cycle."