Distributing new versions is an issue though, as there is no way to tell anyone who is currently seeding the old torrent. But it's not a terrible idea if it turns out there is really a lot of bandwidth (I don't expect that), then I could use my server for seeding at least.

Hmm, that sounds like an interesting problem in itself, a torrent client that handles versioning and updates behind the scenes.

I mean, thats essentially the apple app store right? Just with torrents and documents instead of apps? So like a freely distributed google docs, but for everything. That movie you downloaded a week ago got a better version, the sci-hub article you downloaded last week has commentary from the author or has been disputed, That microsoft office (excel, word, onenote) you've been working on with a group has a long revision history and automatic version control. You could even download the 'latest version' at 'run-time'; when you double click to open the document. There's a company, or atleast the very start of one in these ideas.

Isn't that already solved with RSS?

RSS is widely used to publish new pirated tv show episodes already, so that your torrent client can fetch them automatically when they're available.

This is a solved problem, RSS is used to automatically fetch new pirated tv show episodes.