I think many made the same assumption that I made: A movie can be withdrawn from iTunes or an eBook from Amazon, but if you already bought it you'll retain access, it's just that no new sales can be made.

Regarding BluRays, and to some extend DVDs, I'm in the same boat. I have season one of a TV show, but season two never made it to DVD and now it's locked away in the vaults of some production company, you can't even stream it. There are so many movies and shows that will just be lost in the future.