Jungle might be a bit much but I think you may be on the right track. It seems like the trailers released earlier are spliced together with the End of an Era cutscene and what I assume will be the 2nd part and opening cutscene for ARR.

Check out the characters surroundings and reaction at 0:46
http://www.youtube.com/watch?v=oYMrFXcqvk4
Looks to me like they've just arrived (in their battle gear, WAR still missing his helm) and are quite surprised in what they're seeing.



Also this one
http://www.youtube.com/watch?v=frIJ5CubG1U
at 0:30 (..until now!) they're chocoing through what the area could look like.



There are also scenes with the allied grand companys chocoing through a forest out into a more open area that could be interpreted as them coming from The Black Shroud to Mor Dhona.