I think a lot of one's response to HRT, emotionally speaking, is going to be contextual. If you're someone who's bottled up her emotions, being on HRT -- and actually, just transitioning in general -- is going to open them up. On the other hand, if they already run free, I don't think HRT is going to amplify them very much.
I know that I got very emotional starting transition, which was months before I started HRT. Because I was finally acknowledging the truth of myself. HRT helped me to clarify my emotions and express them more freely, if anything else.