Given the character was a major player in both seasons of The Mandalorian — and an all-around well-liked character — recasting seems like a smart move. Particularly as the character was more than likely intended to play a potential lead role in Rangers of the New Republic.
The Hollywood Reporter has published a report revealing behind-the-scenes details of Gina Carano’s firing from her role of Cara Dune in The Mandalorian and other planned Star Wars series’ in the same timeline.
The trade publication’s inside sources say that Cara Dune is expected to be recast for future live-action appearances, primarily due to story purposes and merchandising for the Star Wars franchise. THR also notes that Carano was never intended to play a role in the next series coming to Disney+ this year, The Book of Boba Fett
Update: The Hollywood Reporter has updated their article to add that one of their Lucasfilm sources has indicated Carano’s character isn’t expected to be recast for The Mandalorian
So, if Disney opted not to recast, and simply abandon the plans for the character, the series would have to be totally rewritten with a new protagonist or scrapped altogether.