A lot of sites out there offer some large quantity of content and then allow users to curate the content they want to consume. Netflix, Disney+, Crunchyroll, Spotify, Apple Music, Plex and so forth.
Almost universally these sites will consider the user’s watch list or album list or whatever to be a curated subset of the content available to the user, but to the user, it’s not! To the user, it’s a curated set of things that are or have been available to them. When they more regions or when the provider loses their license, content appears and disappears from their curated list in a way basically indistinguishable from some random person making changes. Things phase in and out of existence in queues, in playlists, even in usage history.
So I am begging, please, if you ever find yourself allowing a user to curate a set of things, allow that curation to be persistent and signal in other ways that the content is unavailable. Nothing is more annoying than knowing something used to be there and not being able to remember what it was, not being able to go through the list of unavailable curated things and add them to my curated list on the service where they’re now available instead. And a bonus “fuck you” to youtube for the “six deleted videos not shown”. Like, c’mon. At least let me know what they were, who posted them.