Warning: some major spoilers for Black Widow are ahead. Recently, Marvel Studios President Kevin Feige participated in a Twitter Watch Party of Black Widow, and he shared some behind-the-scenes trivia of production while also teasing future developments. One of the most prominent pieces of information Feige dropped was about the fate of Yelena Belova (played brilliantly by Florence Pugh) during the "Blip". A Twitter user asked Feige if Yelena was in fact dusted by Thanos, and Feige gave a cryptic answer by saying, "you will find out, just not on this Twitter thread". He gave no indication as to when Marvel fans will find out, however, but I have a few guesses.
Black Widow took place after the events of Captain America: Civil War and before the events of Avengers: Infinity War. In the same Twitter thread, Feige revealed the reason why the movie was set during this period. He said, "Because we wanted to explore what Natasha did between leaving Tony Stark in Civil War and her arrival with Steve and Sam in Infinity War." In the film, Marvel fans got to meet Natasha's spy family - most notably her adopted sister Yelena Belova. Because the film takes place before Thanos's snap, there is no mention in the film as to what happened to Natasha's family.
However, a post credit scene shows a big time jump with Yelena visiting Natasha's grave before she is interrupted by Julia Louis-Dreyfus' character Valentina Allegra de Fontaine, who was first introduced in The Falcon and the Winter Soldier. Valentina reveals to Yelena that Clint Barton is responsible for Natasha's death (which is partially accurate). Despite the scene taking place after the "Blip", fans did not learn whether Yelena was snapped or not.
Feige's revelation in the Twitter thread, however, indicates that we will indeed learn about her fate in a future Marvel Studios project. Due to the post credit scene, my educated guess is that we will learn in Disney+'s upcoming Hawkeye series, which will debut on the streaming service later this year. Florence Pugh has already been confirmed to appear, and she clearly will have beef with Hawkeye himself as she believes he caused her big sister's death. Because Pugh is not currently signed on for any other projects, it makes sense that fans will learn of Yelena's potential dusting in the Hawkeye series - otherwise, Feige is gambling that Pugh will return in a different project. It would make sense for the show, as it would provide some exciting drama and emotional stakes. If Yelena was indeed dusted, it would mean she awoke to a world where her sister is dead. That could make way for some intense fight sequences between her and Barton.
Black Widow was recently released simultaneously in theaters and on Disney+ as a a paid premier access film. Despite crushing the box office on its opening weekend, it fell off quite heavily in its second week. There are many factors to this, however, and not likely a sign of things to come. Hawkeye will release in Late 2021, although it has not yet been given an official release date. It will star Jeremy Renner as Hawkeye, Florence Pugh as Yelena, and it will introduce Hailee Steinfeld as Kate Bishop.