Maybe he's just not taking a testosterone blocker? From what I understand, it's your body's natural tendency to maintain a balanced ratio of sex hormones, so taking estrogen as a man will actually increase your T levels unless you block the natural hormone.I find this interesting because I've spoken to friends who were MTF and taken HRT and HRT actually can (and is very likely to) reverse receding hairlines in men. The fact that Cosmo's has gotten worse may be proof he isn't taking HRT and isn't really trans as he claims to be.
I only say this because we know he was on estrogen at some point due to the Carpe Diem tweet. But of course, that was almost two years ago, and knowing Cosmo's general laziness and myriad mental disorders, it's perfectly possible that he lost interest in the tranny life and went off estrogen in the intervening time.