But Tomorrowland isn't explicitly about nations of the world coming together in harmony. A lot of stuff was said by Walt on opening day, such as the "and the hard facts that have created America" , which was probably a nod to little boys in love with Davy Crockett, and whether or not it was written by Walt, a lot of generalities and praise are made when something is opened. I kinda think Walt dedicated Tomorrowland to the "the hope for a peaceful and unified world", but Tomorrowland changed from when it opened even in Walt's lifetime.
It became less of a World's Fair, and more of something uniquely Disney, i.e. attractions based in large part of science fiction and excitement over new technologies.
Walt said that Disneyland would be about the "hard facts" that created America . . . but he seems to have glazed over slavery and the first two World Wars, though I guess GMwML gets into the Civil War.