I haven't actually read the 'End of Ever After' novel specifically, but generally, it could be about the conclusion of a long - held state of 'ever after' like the end of a happily - ever - after scenario in a fairy - tale - like world. It might deal with the breakdown of an idyllic situation, perhaps due to some external force, internal conflict, or the passage of time.
Yes, Disney already has 'Solo: A Star Wars Story'. It was released in 2018. However, the movie faced some challenges during production and its box - office performance was not as high as some of the other Star Wars films. But it is definitely part of Disney's Star Wars lineup.
Since I don't have detailed knowledge of the 'after ever after novel', it could potentially be a fantasy novel where the heroes have saved the world from an evil force and now the story is about how the world is like in the aftermath. It might explore how the different species interact now that the threat is gone, how the political structure has changed, and how the individual characters grow and adapt to this new world. There could be new challenges that arise from the very solution that saved them in the first place, and the novel could be all about that exploration.
Since I haven't read the 'after ever after novel', the main characters could be a family. After a major upheaval in their lives, like the loss of a family member or a financial disaster, they each struggle in their own way. One might be a rebellious teen trying to break free from the new constraints, while another could be a parent trying to hold the family together. And there could be other characters around them who either help or hinder their journey in this 'after' phase.
Disney might adapt a horror story by focusing on the story's mystery aspect rather than pure horror. For instance, they could make it more of a detective - like story set in a spooky environment.
I haven't read the 'After Ever Happy Novel' in detail. But generally, it might be about the continuation of the relationship and the challenges faced by the characters. It could involve love, growth, and dealing with past traumas perhaps.