I like the idea of the Mickey ride coming to DLR, but a Frozen expansion of Fantasyland seems like a better fit for the proposed area. There's some super awkward design mojo where Small World, Toontown, and the Fantasyland Theater intersect, so whatever Disney can do to ease those rough transitions and unify Fantasyland would be great. My preference would be to see Mickey go in Hollywood Land, replacing Monsters or the Muppets Theater, but I doubt there's enough room based on what I'm reading about the size of the attraction.
I find the location of Toontown, so distant from the Hub in the back of the park on a single in-and-out path, to be very inconvenient to visit. Ideally I'd rather see a FL "expansion" where the FL Theater is, level Toontown to erect a few large show buildings, and a looped path completely around Story Book Land from Small World through the berm where the Skyway chalet once stood for traffic flow.