GitLab don't have the monetary incentive to implement federation. Most of their revenue is coming from big companies which are mostly using private GitLab instance and won't want their projects federated.
That being said, hope this changes can get merge as somebody already done the dirty work for them. The beauty of open source.
Not specified for this research but... if you rely on LLM to write code that is security-sensitive, I don't expect you to write secured code without LLM anyway