> For things like movies, they should have negotiated a contract where sold copies are sold copies and cannot be revoked (even if their right to sell/rent copies lapse).

It's difficult to see how this could ever be possible without significant legislation changes. Nobody (but nobody) offers this, and in the vast majority of the world you literally can't buy out music rights in this way for any licensed music in the titles. That's why literally no online store offers this.

It works better with music because many stores will sell you a DRM-free mp3. Most movie stores are just “selling” you long-term streaming access.