It's learned Star Wars: Rogue One originally had a different ending, and that director Gareth Edwards wanted the end of the film to go in a different direction than what was revealed in A New Hope.
As we all know, Star Wars: A New Hope revealed the Rebels that stole the death star plans didn't make it out alive, but Gareth Edwards tells Empire Magazine that he originally wanted to have the two stars of the movie survive. Disney's Kathleen Kennedy ended up putting the kibosh on the idea (via i09):
The very first version, they didn’t. In the screenplay. And it was just assumed by us that we couldn’t do that. ‘They’re not going to let us do that.’ So I was trying to figure out how this ends where that doesn’t happen. And then everyone read that and there was this feeling of like, ‘They’ve got to die, right?’ And everyone was like, ‘Yeah, can we?’
We thought we weren’t going to be allowed to but Kathy [Kennedy, President of Lucasfilm] and everyone at Disney were like ‘Yeah it makes sense/ I guess they have to because they’re not in A New Hope.’ And so from that point on we had the license.
I kept waiting for someone to go, ‘You know what? Could we just film an extra scene where we see Jyn and Cassian, they’re okay and they’re on another planet?’ And it never came. No one ever gave us that note, so we got to do it.
While we won't be getting a Star Wars: Rogue One sequel (it's actually A New Hope), it is possibly Disney could do a Star Wars: Rogue One prequel as Felicity Jones is signed on for more Star Wars movies.
"Star Wars: Rogue One" is directed by Gareth Edwards and stars Felicity Jones, Diego Luna, Ben Mendelsohn, Donnie Yen, Mads Mikkelsen, Alan Tudyk, Riz Ahmed, with Jiang Wen and Forest Whitaker. Kathleen Kennedy, Allison Shearmur and Simon Emanuel are producing, with John Knoll and Jason McGatlin serving as executive producers.
From Lucasfilm comes the first of the Star Wars standalone films, Rogue One: A Star Wars Story, an all-new epic adventure. In a time of conflict, a group of unlikely heroes band together on a mission to steal the plans to the Death Star, the Empire’s ultimate weapon of destruction. This key event in the Star Wars timeline brings together ordinary people who choose to do extraordinary things, and in doing so, become part of something greater than themselves.
Star Wars: Rogue One trailer: