The question is can you use copyrighted info to train a model. The answer is we don't know yet.

The current lawsuit that will define precedent on this is for image generation using copyrighted Getty images in a training model. It's proven that Getty images are used because the watermark shows up in the output of the model many times which is the answer to "how can they prove it".

Once that is defined, then we will know if it is legal or not in those jurisdictions. And then we will get to the "do we do it anyways even though it's illegal?"