The trailer really hyped me up and i believe the dynamic of the protagonist being a couple is cool. I dont see the issue with a female protagonist at all, more females play games now than before, turns out a lot of girls also hid their likeness of games to other girls when they were teenagers, and now that theyre adults they see the game they played as little (vice city) with a female protagonist itll of course attract sales.
I dont see how it would affect the story, most of my females friend that said to have play gta also ran around killing prostitutes, stealing shit and causing mayhem like most male players did as well.
Enjoy the game fellas, and maybe touch some grass once in a while.