Comment by echelon
We should be specific when we say "models".
The code outlining the network vs. the resultant weights. (Also vs. any training, inference, fine tuning, misc support code, etc.)
The theoretical diagram of how the code networks and modules are connected is math. But an implementation of that in code is copyrightable.
Afaik, the weights are still a grey area. Whereas code is code and is copyrightable.
Weights are not produced by humans. They are the result of an automated process and are not afforded copyright protection. But this hasn't been tested in court.
If OpenAI GPT 4o weights leak, I think the whole world could use it for free. You'd just have to write the code to run them yourself.
I use model architecture for the code/math and weights for the weights to avoid confusion!
Then there are hyperparameters which are also needed to be known to use the weights with the model architecture.