I've been wondering the same thing. I'm guessing they might leave those up in tomorrowland for a little while, if nothing else to give SW fans something to do when the land is at capacity. It seems unlikely they would 'move' the entire Star Tours building, but maybe they will build up a new Star Tours attraction in Galaxy's Edge, and then re-theme the existing ride to be something else futuristic. Wall-E, Tron, Witch Mountain, Flubber, Big Hero 6, John Carter, The Cat from Outer Space and one of my personal favorites Flight of the Navigator could all be fun.
The Star Wars aspect in Tomorrowland has always been ironic, so it will be nice to have those removed. 'A long time ago, in a galaxy far, far away....'