I think that heavy investment in "IP" almost requires theme parks to turn into fairly random constellations of isolated, unrelated small lands and attractions.
If you want to build a theme park with strong theming ... meaning a coherent look and feel (architecture, landscaping, music, costumes, etc.) ... then you can go ahead and imagine great, original rides which match (and enhance) the theme. Thus you have Space Mountain and the People Mover in Tomorrowland, Pirates and Jungle Cruise in Adventureland, and so on.
As soon as you start leveraging IP, you end up inserting more or less jarring juxtapositions onto your themed lands.
Universal's Rip Ride Rockit was a jarring overlay of their "New York City backlot" theme and it was arguably an IP-based insertion since the main point of the ride is to play pop songs to the riders and then sell them a music video afterward.
Hogwarts is stupendous, but in order to squeeze it into IOA they had to build it so that when you enter Jurassic Park, you literally see Harry Potter's castle beautifully framed under the "Jurassic Park" archway.
So they can get away with a lot of theme-breaking. And have got away. But how far can they go? The unifying mood of a themed land is intangible. it's just a feeling you get from the architecture, landscaping, water features, background music and so on. And it's more than just your emotions, it's in the age, tastes and expectations of the guests who are drawn to a particular area of a particular park. If the various attractions and mini-lands are jarringly unrelated then what's the difference between your "theme park" and any old amusement park? Or the fun fair that sets up in your local shopping center parking lot.
Epcot now has a pretty nice Frozen overlay. But Epcot already tends to attract older, more intellectually-oriented people ... not to mention foodies and party animals. A princess ride doesn't fit in with what they mostly go to Epcot to see, and the rest of Epcot certainly doesn't have any big excitement for the little kids who are most impressed with a Frozen boat ride. If they add a comic-book movie based thrill ride to Energy Adventure then that (and Test Track) will please the teen and 20-something thrill seekers for about 45 minutes. Then what? Ride on Spaceship Earth and watch the France and China movies a couple of times?
If they keep on mashing up their theme parks based on nothing but box office hits of the year and projected toy sales then they'll end up with nothing but a hash ... and their buses will be packed all day with people criss-crossing WDW looking for the thrill "of the moment".