I’m not so sure. Just think about coding assistants with MCP based tools. I can use multiple different models in GitHub Copilot and get good results with similarly capable models.

Siri’s functionality and OS integration could be exposed in a similar, industry-standard way via tools provided to the model.

Then any other model can be swapped in quite easily. Of course, they may still want to do fine tuning, quantization, performance optimization for Apple’s hardware, etc.

But I don’t see why the actual software integration part needs to be difficult.