No. Section 230 protects you if you remove objectionable content. This is about deciding which content to show to each individual user. If all your users get the same content, you should be fine.
If they can customize the feed, does that make it their speech or my speech? Like if I give them a "subscribe to x communities" thing with "hide already visited". It'll be a different feed, and algorithmic (I suppose) but user controlled.
I imagine if you have explicitly ask the user "what topics" and then use a program to determine which topic then it's a problem.
I've got a WIP mastodon client that uses a llama3 to follow topics. I suppose that's not releasable.
