Perhaps he meant when the decision was made internally, as opposed to announcing it to the public via the press release?
-Duke takes a vacation in Vegas, gets attacked by mutated army
-Duke takes the fight to the streets, visiting famous locales
-Duke hitches a ride on a truck as Dr. Proton's nuke hit Vegas
-Duke fights off Army Ants in the highway to escape from the nuke's fire as seen in the trailer
-Duke reaches a US Army base for some reason and meets Bombshell there
-Duke and Bombshell fights across the Grand Canyon to reach Hoover Dam
-They presumably got separated in the Ghost Town
-Duke meets Gus, who tells him to use the mining area
-Duke and Bombshell regrouped there and escapes together
I wonder how accurate I am?
Don't forget the Lake Mead jet ski segment, which was one of the sequences shown to the press behind closed doors at E3 '98. Also, at one point, Duke rides a steam train through the desert/canyon area, manning a Gatling gun mounted on a flatbed railroad car. Here is an article where both of these elements are mentioned, along with a ton of other rare tidbits.