I put a movie on my wish list. Now it's not available. Why?

Love our Apple TV 2 but can't understand why movies and TV show series that we were watching suddenly become unavailable. It's so frustrating to be in the middle of series 4 only to find that now there's only series 1 or 2. Or we'll put a movie on the wish list, and instead of "play" the only option is "remove." Does anyone know why? Thanks in advance!