We know from the prelude comic that after Cap rescued his captured teammates that Clint intended to retire again and stay with his family. So then why does he show back up in Wakanda? And why has he not been in any of the promotional art? Well I have an idea.
What if Hawkeye does retire, but then a Skrull replaces him! That would explain the leaked pictures where it looks like Clint has taken on the mantle of Ronin. Maybe Clint knows a Skrull replaced him, or survived Skrull abduction, and since then has been hiding out under a different persona. And what if the Avengers don’t know he is a Skrull until the Skrull that is impersonating him is killed during the invasion of Wakanda.
I know this isn’t the most in depth idea or speculation, but I don’t think it’s too far out of reality. What do you guys think?