As someone who grew up nearby, there's absolutely no way Chicago gets more tourists than Vegas. Vegas has internationally famous tourist sites and experiences and a dedicated miles-long corridor for them to go, resort fees aplenty, while the only thing Chicago has with comparable international attention is....uh...maybe the Bean, I guess, if you like taking selfies?
Whereas Vegas has multiple huge convention centers, the cirque shows, the novelty architecture, is in countless movies and TV shows, and so on. Nor does Vegas have outdated and persistent statements made relatively commonly in the media about how dangerous the city allegedly is.
I don't see anything or anyone in Chicago freaking out about loss of tourist revenue the way anything that
remotely covers Vegas is doing right now.
This link has Nevada and Las Vegas in the top five for state and city, respectively, while Illinois and Chicago are no where to be found. This link looking at domestic tourism likewise has Vegas far above Chicago.
I'm honestly baffled they picked Chicago for this and if it doesn't go the way of Disney Quest within a few years, I'll be shocked.