We don't have to even get to the point of extending copyright to artistic style. If using copyrighted art to train a model is found to not be fair use, the technology will no longer be above board. Companies in countries with these rules won't be able to ignore them.

What could happen if this interpretation of fair use comes to pass? Model trainers may have to license images from companies like Getty. In a sense, it should be cheaper than using an image individually. In some countries, music organizations deal with licensing large sets of songs, no need to negotiate with each label or artist individually. That sort of arrangement could come to pass. Perhaps there'll be a simple option on image upload sites to select the license for the image - allow or disallow model training. Or perhaps everyone will simply use below-the-board models surreptitiously.