It looks like the stance of FSF is for proliferation of the copyleft to trained LLMs

> "Therefore, we urge Anthropic and other LLM developers that train models using huge datasets downloaded from the Internet to provide these LLMs to their users in freedom"

No, it looks like the stance of the FSF is that models should be free as a matter of principle, the same as their stance when it comes to software. Nothing in the linked post contradicts the description that the judgement was that the training was fair use.