While Disney+ contains 100’s of movies and 1000’s of TV show episodes, there are occasions when titles are removed from Disney+.
There are a number of reasons why these titles have been removed:
The main reason why movies and shows are removed from Disney+ are due to preexisting contracts that had been signed before Disney+ launched. For years Disney and 20th Century Fox have been licensing out their content to streaming services including Netflix, Fubo, HBO, Starz and others. Many of these deals are long standing contracts which run for multiple years, so Disney have to either buy themselves out of the contract or wait for these contracts to expire. Eventually most titles that are removed, will be added back onto Disney+ when the contract expires.
If there is an problem with the title, then Disney will temporarily remove the movie or episode to fix it.