It wasn’t. It is commercial use to train and sell a programm with it and that is regulated differently than private use. The data is still 1 to 1 part of the product. In fact this instance of chatGPT being able to output training data means the data is still there unchanged.

If training AI with text is made legally independent of the license of said text then by the same logic programming code and text can no longer be protected by it at all.