As Avatar provides a very uniquely themed experience I find it more fitting to spur from the Discovery Island hub rather than being located on the Northern expansion pad, saddled up next to Asia and Africa. This option would provide for a better transition.
Location
It has already been mentioned that Festival of the Lion King will be getting a new home within AK, clearing additional space for the Avatar expansion.
Each gate has full-day potential. Many guests just choose to overlook the entertainment offerings and smaller attractions in search of the more thrilling options.