If I had to make an educated guess, I would say it was the fantasy attitude of Vegas. "What happens in Vegas stays in Vegas" that shouts "Demenses".
I think the easier explanation to me is that I heard at least one playtest city was Vegas, so it could just be a shout out/holdover from that. It wouldn't surprise me if some of the other Playtest cities like Winnipeg got similar shout outs in the final release.
I could be way off though. In which case, I am surprised the designers didn't think of that....