If the students are using the works for purposes such as analyzing, critiquing, or illustrating a point, and not merely reproducing them, they have a strong case for fair use. That’s all these models are, original analysis of their training data in comparison with each other. This use is more likely to be considered transformative, meaning that they add something new or different to the original work, rather than merely copying it. If you need it said another way, here’s a link to a video about this sort of thing.