It was confirmed that The Last of Us Season 3 would be headlined by Kaitlyn Dever‘s Abby rather than Bella Ramsey's Ellie. This change in the protagonist was hinted at in the concluding moments of the season 2 finale. Moreover, it also suggested that the third season will play out three days before the events of the season 2 finale.
While this switch in the main character might feel jarring, those who have played The Last of Us Part II would know that this change in perspective is not surprising. Thus, fans who played the game already knew that The Last of Us Season 3 will follow Abby, with very little involvement from Ellie.
The Last of Us Season 3 takes inspiration from The Last of Us Part II, but there's a catch:
In the last act of The Last of Us Season 2, Abby breaks into Ellie's hideout and delivers a devastating blow to Ellie by killing Jesse. She even holds Ellie at gunpoint, but the screen goes black, and all we hear is a gunshot, but we don't know who the victim is. Rather, the series travels three days before this scene, but it unfolds from Abby's perspective.
It is since this scene that viewers theorized The Last of Us Season 3 would follow Abby more than Ellie. This is very much like the game, where the players had to play as Abby. It is in this portion of the game that the player learns why Abby killed Joel. The shift in perspective in the game forced the player to empathize with Abby, even after she killed Joel.
Halley Gross, who wrote a few episodes of season 2 and even served as the co-writer of The Last of Us Part II, addressed why players had to play as Abby for a while in a June 2020 IndieWire interview:
"We wanted the opportunity to build empathy for her from the start, and the most effective way we can do that is to have you walking in her shoes, spending time with her, seeing what makes her vulnerable, seeing what makes her scared. We get that she’s scared of heights, we get that she has a soft spot for Owen and is upset about his romantic life, we get that there are intense stakes that might drive those two people apart. We wanted to inform all of that without you understanding that she’s the prototypical “antagonist.”"
In the game, the player learns why Abby killed Joel as they play as her. This means that the player is unaware of why Abby killed Joel for a long time. It is only when they play as her that they develop empathy for her. But since we are telegraphed the reason why Abby swore and executed her revenge on Joel, The Last of Us Season 3 has to add more to her story. This could be done by adding a flashback episode.
The flashback episode of The Last of Us Season 3 could flesh out Abby's relationship with her father:
The surgeon that Joel killed in The Last of Us Season 1 finale is Abby's father. The pain of losing her father is why Abby swore vengeance against Joel, which she accomplished. But we don't know what Abby's relationship with her father was like.
Thus, The Last of Us Season 3 could add an episode of what their relationship was like, much like the sixth episode of season 2, which showed Joel and Ellie's father-daughter relationship for five years between seasons 1 and 2.
As of now, The Last of Us Season 3 has not begun filming yet.