Between not having the necessary pedals on their boards, patch settings for synths queued up, light show programs, or any multitracks that might have been on a click... I'd say it's more than just being unrehearsed. These tours are convoluted productions and they require dozens of hours of preparation. Can't blame Kev for nixing it, but I hope they get a chance to prepare something older for the later shows. My pick would be "Sundown Syndrome", maybe with a new arrangement? Wishful thinking, I suppose.