Because Black Widow will take place at an earlier point in time than where the MCU currently is, and because this character won’t be moving forward in the story, it does raise a big question about why the Black Widow movie is happening now. It certainly can be a standalone story that won’t lead to any major developments within Phase 4. However, since this is the first movie out of the gate, there will certainly be a lot of interest in trying to figure out just where this batch of movies, and Disney+ series, are headed,
Article source: https://www.cinemablend.com/news/2486041/jeremy-renner-is-psyched-about-the-black-widow-movie