During my "shopping spree" for SRS surgeons I did run across at least two who may be the source of the HRT after SRS misdirection. There are a couple of surgeons who do mention problems with people who have been on HRT for more than 3 years, they use the penile inversion method and do find that the penis on some patients has atrophied so that it is a problem giving depth to the neo-vagina during the surgery. It is actually a product comparison of the doctors who use penile inversion, versus those who use the scrotal flap technique, and a bit of an advertising ploy. The problem does not happen to everyone and is not a sure thing and there are ways of dealing with the shrinkage if needed, but it was how rumors get started. Also, as many of us that really can, would really love to have a much shorter time than three years between onset of HRT and our SRS!!
I am about a week short of two years on HRT but still pre-op, and after about 6 months on E alone, I stopped having erections, but with the stop came almost intense sensitivity to the glans, and an onset of female style horniness, about four months after that, my nipples joined the pleasant sensitivity game as well as other parts of my inner upper legs. The release of the sensitivity is a long period of time, and hits numerous high points (orgasms) instead of the single one that I had as a male. Your neo-clitoris will be made from the glans of the penis, and the doctors have found very good consistent ways to keep the nerve supplies intact and very sensitive within a few months or less of recovery from the surgery.