I think there's been a lot of mis-direction by Marvel regarding these movies, and by design. I don't blame them. But, based on that article, and reflecting back to an interview with Feige where he mentioned that A:IW would be very Thanos centric, I have to believe that A:IW will be almost from the perspective of Thanos to some degree. His journey to get the stones, and in the meantime we get to see him wreck shop against the characters we all have watched for a decade. I think that A4 will then be the team we know coming back together to stop this threat that was just developed over a really intense movie. (That may be way off base, but even with a decade of teases, Thanos still isn't really a big threat. I think he has to "win" A:IW to some degree for a big payoff victory to happen in the 4th movie.)