Yes, HRT does visibly reduce the size of the shoulders a bit, because it takes a lot of the muscle away and thus makes them look bonier and thinner rather than broad and strong, but they'll still be wide. It's just one of those things that we can't change, and we just have to accept it and learn to cope.
With that said, I started noticing them looking smaller by around the 9-month HRT mark, and the muscle has slowly but steadily been melting away ever since.