I rewatched season one and two, and in that scene I was really hoping that she'd try bending or something, but she never does. She goes straight to the tree of time and turns into the blue Korra and has a power rangers style battle with Unalac. I'm not sure if she would have been able to use the other elements or not. Raava didn't restore her bending when Amon somehow severed her connection to the other elements using physical bloodbending. I wish there was more information on this throughout the series. My guess is that if she in fact was severed from airbending, if Zahere ever lost airbending he would still be able to astral project. Not sure tho