You can't turn it off anymore in Golden Gate. It is a mandatory download (in countries where it is supported) now.

You can still disable some specific AI-related features, but you can't block the models entirely.

I have mixed feelings about this. On the one hand, that's a ton of disk space, and Apple is notoriously chintzy when it comes to storage. On the other hand, I do want the default to be local-only models, and giving developers easy access will make that the path of least resistance. Most of my problems with LLMs don't apply to moderately-sized local models.