Although MCU fans have been crying out for a Black widow movie for years, Marvel has taken so long to make one that is now unequivocally dead. Then, on the other hand, he will deepen his past more than the unsystematic offers we have received so far, and a prequel comic now puts a previous reference to his actions in a new light.
The first of the two themes Black Widow: Prelude see General Ross hunting the members of the Cap team after Captain America: Civil War, and uses a government official who needs to be informed about the former assassin as an excuse to recap its origin, with some additional details. Ross says he joined the Red Room after calling the attention of his supervisor, General Dreykov, which would be so insignificant if it weren't for a moment in The Avengers.
If you remember, the scene between Nat and Loki in the S.H.I.E.L.D. Helicarrier is remembered mainly for the old-fashioned and somewhat risky insult that Nat is a "meowing quim," that is, the only moment in the film in which someone psychologically overcomes the intriguing cheater. Relevant to this is Loki's failed attempt to get into Nat's head by listing the terrible things he has made that made her feel as if she were beyond redemption.
Specifically, it mentions "Sao Paulo", "the hospital fire" and "Dreykov's daughter". While at that time it was not unreasonable to assume that these were murders carried out on behalf of their KGB managers, having one of their most guilty memories was the unspoken atrocity committed against their supervisor's son raises some new questions about the uncounted aspects Of your past.
As ComicBook.com explains:
Many Marvel fans assumed that Loki's complaint followed the central theme of terrible things that Natasha had done at the service of the Black Widow program, but the Black Widow Prelude comic re-contextualizes that story completely. Now it is clear that what happened between Natasha, General Dreykov and his daughter, was part of Natasha's turbulent and undoubtedly violent departure from the Red Room Program. It will be interesting to see if General Dreykov and the past incident with his daughter have something to do with the forces that come through Natasha when she returns to Russia in Black Widow. If so, the connection between that story and Avengers would be an impressive MCU retcon.
It is entirely possible that the circumstances that instigated the altercation were those that led to his defection, and whatever he did to the nameless girl was what caught the attention of S.H.I.E.L.D. "In the worst way." Black widow will explore Nat's past and training, this moment is likely to be reviewed, since the circumstances surrounding it may have formed a crucial moment in his personal history. Not to mention, taking out and recontextualizing an oblique and disposable line eight years ago would be a somewhat arbitrary choice if it wasn't given a new meaning, right?