Learn all about the evolution of Jyn Erso, the missing opening crawl, and the nixed happy ending. - From Quartz
Others, like the scene where the TIE fighter rises to confront Jyn on the Imperial tower, were cut from the movie early on, when the filmmakers were still figuring out what the right version would be.
Despite her early reluctance in the movie, Rogue One‘s main character Jyn Erso was always meant to be the leader of the ragtag group of Rebels who band together to steal the plans for the Death Star, the early concept art revealed.
In an early screenplay, Ahmed was supposed to play Bokan, an Imperial engineer who was kidnapped by Saw Gerrera and developed Stockholm Syndrome after years of living with him, Ahmed told EW.
(Part of the reason that Gerrera was never found by the Empire is that he modified his ships to survive in that environment where nothing else could, Whitta said.) Bokan would have helped them repair an old Imperial shuttle found on the planet.
This explains some of the footage from the trailers that was missing in the finished movie, which was broken down by Slashfilm.