I still think that if Uni were to ever work with Nick again or with Cartoon Network, it'd be really cool if they made it something like Star Tours where it could easily update. As one show ends, just update the film with a new cartoon. I know everyone hated Jimmy Neutron, but a version of that ride with a newer ride system in Toon Lagoon that could easily update to not become outdated could work IMO.
I don't think they will ever go back to that method of just a simulator ride for an IP if the environment is actually immersive (i,e Transformers). It most likely will be full fledged or a mini land.
Universal does own their own toons in particular Curious George and the Land before time but neither of those would fit the thrill of IOA in my opinion and are geared much younger than the rest of the park. As for the Nick VS Cartoon Network, I am going to say Universal would better off going with Cartoon Network than Nick as a lot of Cartoon Networks shows also are attracting not just youth but adults (i.e Adventure Time and Steven Universe in particular) and also Nick is falling hard in the ratings outside their preschool shows and I am also thinking that Comcast/Universal wants young children but not those under the age of 3 as they truly make no money off them as well as strollers being a nuisance. Outside of SpongeBob, there are no real popular toons, (TMNT really isn't popular based on the ratings its getting with young kids and current film success (which is minimal) is probably due more to Nostalgia than anything). Also Cartoon network will be the best as they have the top 5 of ten most watched shows by kids 6-11 as of last year and top seven of ten of most watched show by boys 6-11.
I would want to see:
SLOP ride/NYC with minion elements and SING elements.
Change out Dudley Plot for a super weird and crazy Adventure Time ride and full scale miniland (like Kong) and make it full indoor as everything in IOA is outdoors which sucks when it rains.
Change Popeye's theme to SpongeBob with a Krusty Krab quick service and change Me Ship, the Olive into SpongeBob/Patrick and Squidwards house/playground area.
Minimize the food court next to TL theatre and change it a Steven Universe Gem musical/dance show and restaurant.
I love Popeye but I think if they are going to pay Hearst just for him then its not worth it. At least with Boop with the rights being so convoluted Universal has a upper hand.
The interesting thing to note is each is a very different animated style which would potentially add to the zaniness of making it feel as a real toon lagoon.