I always hear contradictions to this theory, but I am fairly sure that the hat was always intended to be permanent, and was placed there because of PhotoPass. I think the rights to the image of the Chinese Theater are owned by someone other than Disney, and that whenever Disney sells something with that image on it, they have to pay that owner. (This would also explain why the mouse-eared water tower, and not the Chinese Theater, was the original Studios icon -- so they didn't have to pay royalties on D/MGMS souvenirs that displayed images of the icon.) Needless to say, Disney sells countless photos shot down Hollywood Boulevard every day via PhotoPass, and to keep the Chinese Theater out of those photos, they built the hat. If I'm right, it won't be moved anytime soon for this reason.