I'm actually really hoping they don't increase the roster at all for the next movie. Yeah, I would like to see some characters on screen we haven't yet. But more importantly, I don't want the series to get bogged down with too many characters. This one was great in that they were able to give everyone something good to do. I don't want them to compromise that just for fanservice.
I would like to see a Hawkeye movie. And before this movie, I NEVER would have even thought I would say that. Same thing with Black Widow.
I really want to see an Agent Caulsen moovie, though. I think if they did that, it would be successful.