>>116521021This is a common misconception, made worse by Disney's increasingly infrequent acknowledgement of the film.
Roger Rabbit is a Disney IP. It was produced and animated in-house and was released under their Touchstone Pictures banner (intended for live action pictures that didn't fit the traditional animated musical formula). The difference was that they had to seek permission from Warner Bros for the use of their characters. There was actually a stipulation as part of the deal that their characters could not be made to appear inferior to, nor occupy even a second less screen time than, the Disney ones. This is why the piano duel ends in a draw and why Bugs and Mickey enter and exit the frame during their scenes in precise synchronisation.
The film was additionally funded in part by Amblin, such that every time they want to use the IP they have to pay Spielberg a 50% cut. This presumably is why they have gradually lost interest in featuring the characters in the parks etc beyond special occasions.
But in short, it's Disney, just with a multitude of complications.