Black Widow has a post-credits scene associated with the as yet to be released Marvel Studios series. The scene takes place after the death of Natasha Romanoff in Avengers: Endgame, her main character is Elena Belova, Natasha’s friend.
At the cemetery where Natasha Romanoff is buried – apparently, this is a cenotaph – Belova meets with Countess Valentina Allegra de Fontaine. She is played by Julia Louis-Dreyfus, and she first appears in The Falcon and the Winter Soldier.
The Countess makes Elena an offer: why not take revenge on the man responsible for the death of Romanoff? Obviously, we are talking about Clint Barton, with whom Natasha went to Wormer. Romanoff voluntarily sacrificed herself, but Elena has a different point of view on this story.
Belova agrees. It can be assumed that her hunt for Clint Barton will begin in Hawkeye, the next Marvel Studios series, which is scheduled to premiere in 2021.
Another interesting point: this is the second appearance of Countess de Fontaine in the MCU. We first saw her in The Falcon and the Winter Soldier, where the Countess similarly recruited John Walker, the former Captain America.
It is assumed that Countess de Fontaine assembles a team of Thunderbolts, superhero opponents of the Avengers. We don’t yet know why she needs it, but in the comics, de Fontaine had an interesting track record and a long history of betrayal.