More detail in: https://x.com/XOpenSource/status/2087951962004230428

And the actual repo: https://github.com/xai-org/x-algorithm

> We’re releasing the code that determines how posts are ranked and filtered in the For You timeline, including the content labels that can impact post visibility. This builds on our previous open-source work, adding model configuration, filter and core ranking system details.

They've been saying that for years.