nolva upregulates the expression of the progesterone receptor, as relates to gyno this likely not a good thing with progestins (keeping in mind that receptor binding (between individuals(receptor subtypes and isoforms) and drugs) varies- basically not all progestins will have the same activity at the PR in breast tissue).
basically in most people nolva + tren or deca= bad news. In some people its other effects might supercede that or that increased expression might be good-- in theory. Though generally mixing nolva with them is a bad idea and significant time between cessation of those drugs and the use of nolva is reccomended.