Still this argument which is not true. Even if the movie is gone from the apple store it will still be in your purchases history and available for play via streaming.
Same for music. I have at least 10 albums that are I incomplete and not available anymore in the iTunes Store but I still have them to stream or download. Let's put this rumour to rest please.
Nope. I bought Coldplay 2012 from the iTunes Store in 2012. It was subsequently removed from the iTunes Store and it disappeared from my purchased movies list. Fortunately, I had downloaded a copy. It was recently added back to the iTunes Store, but Apple tells me that I must re-purchase the movie in order to watch it (via streaming on the Apple TV or iOS device).
Specifically, Apple sated that "it appears that the movie probably got modified. When an item is modified in the iTunes store, or removed entirely, we no longer have access to the original one that you ordered. If you wish to watch this again, you will need to purchase it."