I did be very emotional for the first one when it was re-released in China. It reminded me of the pure power that cinema could and should have. Even though it is a movie involved large of CGI stuff, Cameron didn't get lost. He know exactly how to bring people into a new world at the emotional level instead of just gorgeous look.
I'm not surprised that Avatar 2 will be the same. Cameron like to tell a family-relations-like story in sequels. In Aliens, it's Ripley, Hicks and the girl in alien planet. In T2, it's Terminator, Sarah Connor and her son. In Avatar 2, it would be Jake Sully, Neytiri and the adopted human child who couldn't go home but stay here (it's not spoiler).
I guess in the Avatar 2, the human child feel lonely because few people, maybe only Jake, accept him. Neytiri don't like him at the beginning but change her attitude as human hunt them. And at the end of the second act, Neytiri accept the kid. Three of them finally fight as a family with human, just like what those characters did in T2 and Aliens.