I don't see Scott in that clip, and I'm pretty sure he wasn't in the credit scene in Captain Marvel either. If so, I'm guessing (with questions)...
- Captain Marvel answers the page, shows up at Avengers HQ, where it's Cap, Thor, Black Widow, Hulk, War Machine, and Rocket.
- CM + those named above see that Thanos used the stones again, decide to go after him. But how do they do this before Tony and Nebula make it back to Earth in the Milano? Tony and Nebula aren't on board whatever ship it is that those above board to go after Thanos again. So what ship is that?
- Tony and Nebula fix the Milano, make it back to Earth.
- Regardless of the order, there then looks to be some kind of fight with Thanos relatively soon after? Do the Avengers lose again? Do they retreat?
- Because then we've seen clips/shots of just Cap and Black Widow back at Avengers HQ, looking even more depressed than before. That's when Scott shows up.
- At some point around this time Black Widow runs into Hawkeye, who also rejoins the team.
- Then we've seen shots of the whole team - the initially remaining Avengers + Tony + Nebula + Scott + Hawkeye - but MINUS Captain Marvel - all back at Avengers HQ, prepping for ANOTHER mission, this one presumably having something to do with time travel?
Ha, no matter how much I try to piece together what we've seen, it still doesn't quite make sense, and I love that. The marketing so far has been PERFECTLY vague/teasing/confusing.