The appearance of Bruce Willis’ Unbreakable character at the end of Split required special permission from Disney.
The film follows up both Shyamalan’s Unbreakable, from 2000, and his Split, from earlier this year, the latter of which featured a post-credits scene that brought the films’ universes together.
Furthermore, there is the question of the genres matching, as Unbreakable was more of a suspense film, while Split fit more in the horror genre.
According to THR, the Glass production required the combined efforts of both Universal and Buena Vista, a subsidiary of Disney, as the latter company released Unbreakable and former was responsible for Split.