They may not be Disney, but they want to be. 

Anastasia, Quest for Camelot, and Swan Princess are infamous for trying to emulate Disney movies. The reason being that Disney was rocking the box office, and everybody wanted in on that. Quest for Camelot is kind of infamous, because the team who made it was trying to be the anti-Disney at first, but was squished by corporate Higher-Ups to be more Disney. Leading to the very cluttered and confusing mess the movie became. Anastasia is by Don Bluth, who was the former Disney Golden Boy. So it’s the closest thing to a Disney movie, without having any Disney money behind it. And Swan Princess… Let’s not go into that. 

So while you can say they’re not Disney, that doesn’t mean it wasn’t the intention. All 3 where trying to cash in on the Disney movie craze, by copying Disney, shamelessly.