When asked about Weaver's character returning Avatar 2 and 3 Cameron asked, "[Have] you ever heard of nonlinear storytelling?"
He goes on to explain, "A lot happens on that planet before she shows up, and before Jake [Sam Worthington] shows up to join her. She's there for fifteen years ahead of time. I don't know, but I wouldn't jump to conclusions. And I've already said way too much about Avatar 2 and 3 here and there, but people piece it together like those voice cameos and tell the whole story!"
So it sounds like we're either going to be looking at prequel material or flashbacks or both. Personally I wouldn't be surprised if Avatar 2 was a prequel of some sort that suggested an alternative for the Na'vi after their home tree was destroyed as well as introduces a long-ago enemy of theirs and then Avatar 3 explores that alternative and has that long-ago enemy return now that the humans are out of the way. Just spit-balling.
Excited about Avatar 2? News are now slowly wrapping up, just like they did a couple of years ago. Can't wait to keep posting news such as this to keep the fan base pumped!
You can read the entire article HERE.