Yes, they both care about money, but you know what else is important to Disney, branding and reputation. While they have zero control over what's alread there, the last thing Disney would want is for them to have an MCU related addition that could lead to IoA topping DAK or especially DHS. As you know, both of those parks are receiving major enhancement, so they would want to keep Universal from using the MCU (aka, the Disney owned epicenter of 2010's cimema) if they have any control over it at all. If Universal some how ends up using the MCU for future additions and its because of a contract re-negotiation with Disney, it would create a lot of bad press on Disney's front because they would be willingly shooting themselves in the foot. Yes, Disney profits from Marvel Superhero Island, but not as much as they would for even the cheapest addition to one of their parks. In short, no major corporation would be stupid enough to allow their competitor to 1-up them even more than some people already think they're already doing on their own.