No, even if you somehow were able to download the corpus of all public X posts. There are many hidden signals that are feature engineered in good recsys, and the stripped-down algo won't be able to replicate them.

It would cost a fortune in API calls, so it's not practical for anyone except internally at corporate.

well, Bluesky and Mastodon posts would suffice, but it's still useless because of how redacted the release is

I feel like bsky and mastadon only represent a subset of users, so I'm not sure how well you would be able to create a general rec system similar to twitter's from that that is useful outside of those places