FreeSSM is already open source. It's reversed Subaru SSM diagnostic protocol and wrapped a tool around it. That was ~15 years ago, long before any of the AI stuff.
The point was rather that reverse engineering the CAN-bus protocol or existing software that already does it for your vehicle of interest is now by far easier through the usage of AI models than it was before - FWIW I could have done it before with the technical skills I have but ROI for me personally was too low. Now I am really considering it.