Well, it can. It would just be messy and ham-fisted. There is no set rule that the returning hero must be male, only that he is every time so far. We can infer that it must be a male, but they never really say it. Not that I think they necessarily should gender swap just because they can, but it could technically fit in with the rest of the games. They would have to also majorly change some other characters too though to support such a wild departure. Like, Zelda isn't even royalty change. Like a game where things have changed drastically politically in Hyrule, that might just fit in alright, as far as stories go. It's supported by the cycle of reincarnation thing. I just...wouldn't suggest they do that...ever...