With respect to Spielberg, I've enough heard talk over the years (and not just from theme park gossipy sources) to feel comfortable believing that he was absolutely displeased when Hollywood got rid of E.T. Anything beyond that has just been speculation.
Whether he has any power to exert over Orlando's operations, or would even care to, is unclear. I'd love for him to try, but I know I'm clearly in the minority about that on this site.