Besides, the finalized ending of Rogue One flows seamlessly into A New Hope.
Narratively speaking, it makes sense that all of Rogue One’s main characters died, as within the Star Wars timeline, they’re nowhere to be seen or even mentioned during A New Hope or subsequent stories.
Sure a few could have survived, but by going the direction they did, the ending felt more shocking.
Now the Death Stars plans are in Princess Leia’s hands, and with Orson Krennic being killed by the very weapon he poured his sweat into for nearly two decades, Tarkin is the new overseer of the the planet-killing space station.