Hi all
Let's separate out three related concepts: love, sexual attraction, and psychology. If you love someone, chances are that your love will remain strong regardless of HRT, and maybe even become stronger if you work positively at your relationship.
The sexual attraction part becomes harder to nail down, but let us say that HRT (estrogen), may make some transwomen more sensitive to how men smell. This was my case, at least. But whether HRT itself may change your orientation, I think this is more debatable. (For example, pumping a gay man full of testosterone is unlikely to make him straight, you'd probably agree.)
The psychology part: many of us, when we transition, have to do a lot of questioning, and part of this could take us into the territory of whether our public orientation is indeed our true orientation. Many people impose upon themselves an orientation for reasons which are guided by morals, personal goals, and social acceptability. So it is possible that some people, as part of their transition, may question their true orientation and decide that hiding it is no longer necessary.
Therefore, taking these three things together, yes, someone's orientation could change. But, Gabrielle, the HRT is unlikely, of itself, to change you. If anything, HRT would give you an additionally overlay on top of your existing sexuality.
I would classify myself as innately bisexual,and I had relationships with both genders before I transitioned. That hasn't changed, but I did, finally, stop feeling guilty about my sexual choices - that was the key change.
Regards to all!
Julia