Rogue One: A Star Wars Story could prove to be the first in a long line of Star Wars “Anthology” films that are not part of the franchise’s central storyline (which continues in 2017 with Star Wars: Episode VIII).
James Luceno’s Star Wars book Catalyst: A Rogue One Novel serves as a prequel to the Rogue One movie, revealing the extent to which both Krennic and Galen Erso (Mads Mikkelsen) – the father of Rogue One protagonist Jyn Erso (Felicity Jones) – were involved in refining and completing the first Death Star.
Just because the “Anthology” Stars Wars movies focus on different protagonists than the Episodes do, that doesn’t mean iconic Star Wars characters won’t be appearing in them.
Case in point: Rogue One tells the previously-untold story about how the Rebel Alliance stole the Galactic Empire’s plans to the first Death Star and features appearances from none other than the Empire’s second-in-command, Darth Vader.