In the 90s, Lucasfilm strongly pushed the Star Wars novels. Timothy Zahn wrote the Thrawn Trilogy. I probably bought as many as 50 Star Wars books wanting to read about what what happened next, before, and during the movies.
I suspect the strength of all our interest is what made Episodes I-III possible. And Disney seeing the continued strength of the brand made VII-IX plus Rogue One and the coming Solo movies appeared obviously good moves.
However, I dunno what to think about Thrawn.
When Disney bought Star Wars from Lucasfilm with the intent to make more movies, we fans in the early days thought “Heir to the Empire” starring Mitth’raw’nuruodo (aka Grand Admiral Thrawn) was not likely the next story because it took place five years after Return of the Jedi. That movie should have been released around 1988. We figured back then on a Jacen and Jaina Solo (the force sensitive twins of Han and Leia) story. Then Disney dissolved all this material into the Legends. Fan theories show people still want to believe in the old material.
Thrawn is evidence why we continue to have faith some of the old Expanded Universe stuff is not permanently dead. Disney brought him back for the Rebels series foreshadowing and expanding on Rogue One. They have expanded his character so much they even tasked Timothy Zahn to write a novel chronicling his rise. First he was the future, then he was banished, and now he is back.
So… Bring back Mara Jade!