I did wonder what they would do after the big three books were released.
Not sure what else this brings to the table that wouldn't be covered in Age of Rebellion though...
(And Rebels is pretty iconic with why I was unhappy with the style of releases the game did, as you really needed all three BIG hardcovers to accurately represent the crew of the Ghost.)
But it is a good era for stories. Lots of rebel cells and events, lots of alternate crews that join the Alliance.
I imagine a Clone Wars book will follow. Maybe one set prior to Epsiode I as well. Twilight of the Republic