It's not clear whether the DLC was cut or is still in development
A couple of images taken from the portfolio of a video game artist suggest that the development team at Superbot planned to create a level for PlayStation All-Stars Battle Royale based on concepts taken from Gravity Rush and Journey.Ky Bui, a former environment artist working at the company, is the author of the images. It’s unclear whether the Journey and Gravity Rush mix was set to appear as downloadable content or it was cut from the original release.
PlayStation All-Stars Battle Royale was created by Superbot but development and maintenance duties are currently handled by Sony Santa Monica.
Recently, a leak has also showed that DLC based on Legend of Dragoon was also planned for the game but was abandoned.
Journey was one of the biggest indie hits that Sony has ever launched on the PlayStation Network service.