The big news out of the Star Wars literature panel at New York Comic Con? A Thrawn sequel from Timothy Zahn is coming summer 2018. Thrawn: Alliances will also feature Darth Vader, because why not, I guess.
Since Thrawn pretty much butts up against Thrawn’s appearance and new canon debut in Star Wars Rebels, there’s some speculation that the book could be set after the cartoon… Which could mean that he’ll survive the show’s final season. Maybe. In any case, the book is already in the hands of Del Rey.