Implications for Negativity Bias in Dreams

Check out the abstract of this paper, by way of Mungowitz. If dreams carry a negativity bias, as the authors says it does, how should we apply this to our life? Does the advice to "sleep on it" become better or worse, presuming that the reason you sleep on it is that you will better pull together the relevant information in a way that is analytically useful? Is the negativity bias cumulative, so that the more nights I sleep on a topic the more negative my bias becomes?