Although the Black Widow movie tells the story of Natasha's events between "American Team 3" and "Reunion 3", it introduces many new characters.
Of course, there are also familiar faces that will appear in the movie, such as General Ross, Hawkeye (possible), Iron Man (possible) and so on.

Among them, the news that Iron Man might appear in "Black Widow" was reported by Deadline last September.
At the time, although Downey denied the news, fans still believed that there might be previously unexposed Iron Man footage in the film.
However, the latest rumor now is that there won't be a shot of Iron Man in Black Widow.
A Twitter user named Amit Chaudhari broke the news that "it confirms that Tony Stark will not appear in the Black Widow movie." ”
Another informant who knew the film said the same thing, there would be no Easter eggs in the movie. This is really questionable. I don't know if these official staff are trying to hide something. ”
Maybe there's nothing hidden, and Iron Man probably won't appear in the Black Widow movie.
After all, Downey has said many times that he has stepped down and that his journey in the Marvel Cinematic Universe is over, so the possibility of Downey starring in the Black Widow movie is really a bit small.
But whether it is a shot that has been filmed (but not used) in the previous "US Team 3" period, you need to see the positive film to verify!
Black Widow is scheduled to be released in North America on May 7, 2021.