Which part? The Incredibles being closer to Marvel, because Marvel and Pixar are Disney properties? Or the fact that a Disney heroine would be out of place in a DC based game?
If the former, I know that The Incredibles are the property of Pixar Animation Studio and not Marvel. But I was implying that they would be more likely to feature in a cross-over with Marvel than DC.
If the latter, I understand that technically the author of the game can put whomever they like in it, but again a Disney cross-over would be less plausible than say Vertigo comics which is owned by DC. Or something like Harry Potter whose movie rights are owned by Warner Bros, who also own DC.