I've always thought the logical thing to do if bringing Avatar anywhere else in ride form was simply to clone FOP. The R&D is done on it, it's now an IP that not only has one almost $3B movie based on it, but another that's the third highest grossing of all-time so I think it's fair to say the IP has proven itself in terms of popularity and staying power now. Nixing the Innoventions building for Flight of Passage (as someone else suggested) would be an essential expansion of the park since there hasn't been an attraction in that building in years, let alone one that has proven incredibly popular with guests like FOP.
The whole "experience" thing could still just mean a Launch Bay type thing, but if we Remember, Launch Bay as an Idea was created to get the IP a centreally located spot in both DL and DHS while the new lands were being built. There may be some sort of Experience that comes perhaps to the building in Hollywood that has had the Avengers gift shop. I just find it hard to believe that while there may be a smaller thing, there still won't be at the very least FOP added at some point.