Just one little detail to be more accurate. Skybox (or rather sky and light settings) used in Elwynn Forest is base and you will have it everywhere where no other skybox in light.dbc is set. So in every map where no skyboxes are set, this one will apply. There might be, however, overwritten base skybox by some which has coords and radiuses set all to 0, but its not common and not case of eastern kingdoms map.