Dude, I was so pissed off, but then I got to thinking.
In Supermacy, there was a scene where her and Jason were talking about his training and she was looking at him like she wanted to tell him something about him and her, but then just said "you don't remember, do you". I thought for sure it would be written in that they were together at one time in Ultimatum. Then in Jason Bourne.
So, I may be thinking too hard and hoping about this, but there is no doubt Marie is dead, she done. But I think the way they left it with Nicky, its possible she survived. Lulz, probably not, but I ain't excepting she's dead. There is talk of another and if it is, I think she comes back.