I thought of two more ramifications of this.
The first is the career of Harry Reid. Reid was a lawyer who was appointed by the state of Nevada to regulating the gaming industry. He did a good enough job to get him elected as the Congressman from essentially Las Vegas in 1982, then he won a close Senate race in 1986 and spent thirty years as Senator as Nevada. Reid's two biggest accomplishments as a federal legislature was in blocking a plan to use social security to goose the stock market that the GW Bush administration floated in 1985, and to be instrumental in getting the Affordable Health Care act passed. Butterfly away Reid's political career, which no Las Vegas probably does, and there is a good chance you could see no ACA and social security pretty much destroyed, though if social security had been funneled into the stock market that might have delayed the 2008 financial crisis. So you have that.
Also, Hollywood really likes setting movies in Las Vegas. Off the top of my head, "Godfather part 2", "The Hangover", "Diamonds are Forever", and "Leaving Las Vegas" (of course) are all set mainly in Las Vegas, and "Rain Man" has some critical scenes in Las Vegas. Its pretty much a feature of every cross-continent road movie. No "Las Vegas" changes this, and even an "alternative Las Vegas" changes this since the alternative version would have a different look and feel.