Yeah but making a movie to retain the rights is different. If they didn’t make a fantastic four movie, then ALL of the rights would revert to marvel and fox would never make another penny off of that property. Fox would never strike a deal like Sony did to share the rights to a property, because they want to retain as much of the profits as they can. In this instance, the rights are already shared. Disney/Lucasfilm holds the rights to the property, and Fox the distribution rights. Both studios stand to make money off of a release, so it’s a much more feasable deal to be made. I doubt fox would pass up an opportunity to make money off of these films, especially when their time for owning the distribution rights to ESB and ROTJ are so limited. They’d want to cash in on those films ASAP.