Commonly called Reflex Hyperandrogenicity, RH, RHA. It's existence is questionable, as it's only discussed on hair loss forums. I think the idea actually came from a couple of vague statements by hair loss doctors combined with prostate cancer studies and all the reports of shedding on finasteride.
However, there was apparently a more recent study on healthy BPH cells that showed the number of receptors do in fact increase in response to treatment, raising this possibility for hair follicles.