Two things:<p>Should it matter is not the right question. The science will tell us, and understanding differences among people is never a bad thing. We are all different.<p>Celebrate that, work to mutual respect and understanding and equality in terms of gender role freedom. In my view, that is the outcome of successful feminism.<p>Do the brains of trans people change over time once they transition? If so, we have an opportunity to get otherwise hard to get data. They will go through experiments, of a sort ethics would very clearly bar (and should), as they seek harmony between mind and body.