They slipped in that comment about timestorms and avoiding them and snaps of ant man interacting with Tony, Cap, and Loki in their battle of New York costumes have already leaked. so I think those might have significance in Avengers 2 mudkip
They have also casted a teenage Cassie so who knows how these time vortexes work.
I'm guessing hetime warps to the future and we see the world that has been impacted by the snap years later. This gives the chance for the movie to explain what has happened in the meantime. Maybe from there they figure they can use the time warps to travel backwards. ---