Training alone, perhaps. But the way the AIs are actually used (regardless of prompt engineering) is a direct example of what is forbidden by the case that introduced the "transformative" language.

> if [someone] thus cites the most important parts of the work, with a view, not to criticize, but to supersede the use of the original work, and substitute the review for it, such a use will be deemed in law a piracy.

Of course, we live in a post-precedent world, so who knows?