Can you imagine how much of a blast of energy a final encore of Gone/UTEOTW/The Fly would be? You'd need to put that combo at the end because I wouldn't be able to stand after it no matter what. If it opened a show I'd be wrecked for the rest of the night anyway.
Maybe you omitted it because it's the winner in everybody's heart and it would be cruel putting other inferior songs up against it? This seems a reasonable explanation to me.