The reason it worked back in the 90's was because there WERE NO other SW movies, all you had were books to continue the adventures. You weren't just waiting around needing something to fill in gaps until the next film(or the outcry of something that could've/should've been in the film in the first place so you release it as a novel or comic), you just wanted the adventure to continue and that's all there was. This is just a cheap and lazy effort to cash in without giving us a good story onscreen. If you NEED ancillary materials to complete a story, you failed. They can ADD to it, or continue the story/adventure...but it should not have to be read to answer questions to the main story.
Yes, the EU did do stories like that, like "Shadows of the Empire", but those were NEW adventures, not filling in gaps we probably should've had in the Films in the first place.
I'm as interested in this as I was for the comic where the Dr. had a stupid crush on Vader, which is to say not a damn bit. They lost their chance with me and when they put out stuff like this it tells me they(Lucasfilm), don't know how to do anything anymore.