The real question is, why does Link need to be female? Just make an original female character who everyone can enjoy. Last I heard characters like Chun Li, Lara Croft, Claire Redfield, Ellie from The Last of Us and Samus Aran were a big hit with gamers.
Changing the gender of an established character like Link reeks of appeasement of hardline feminists who've probably never played a game in their life. Why should developers bend the knee to make them happy?
I think there is a misplaced idea that because you used to be able to give Link any name there should now be some kind of character creation option.
At least that's a way I can look at it where it kind of makes sense. In the past they had limited space and time so you had one pixel model for the main character but you were able to change their name to whatever you wanted.
I believe some of the early Zelda games have "easter eggs" where if you enter "Zelda" as the character name something will happen?
So it certainly seems like a normal progression. You used to be able to change the protagonist name but now that tech and everything has moved forward you should be able to change the character entirely.
It just so happens though that since the early Zelda games Link has become an iconic Nintendo character and so asking "why isn't Link female" is like asking "why isn't Goofy a cat". It's dumb.