What SEO problems? Organic search results are geotargeted, so it’s not like people traveling to or living in Vegas will mistakingly think have to go to Hollywood to experience Scarecrow (and vice versa). It won’t have a negative effect on marketing, either. They’re building on the Universal horror brand and Scarecrow is part of that. The Venn diagram of HHN goers and UHU goers does not overlap nearly as much as everyone here thinks it does.
There’s no real indication UCM isn’t happening this year. In fact, given the Slash confirmation, there are more signs pointing to it coming back.