Just their typical 4th stuff. Resorts dont really do anything out of the ordinary.
MK does their 4th fireworks on the 3rd and 4th, Epcot adds a little something patriotic to Illuminations, and MGM actually has fireworks, one of the rare times they do. Too bad the hat disrupts the view.
Epcot is the location of choice, MK and MGM are like zoos. They dont hold crowds as well as Epcot, and on a day they will reach some level of closure due to crowds, you are best advised to avoid them.