I think a better counter example is mpeg and other lossy formats. But again, the format does nothing but carry the original even if it’s not a perfect reproduction. You can’t use it in any other way. Its expressed intent is the reproduction of the copyrighted material with no modification or improvement or derivation. These models are not trained with the intent or purpose of only producing the copyrighted materials. It requires your specific action to induce the reproductions if it’s even possible, but it generally serves other purposes in all other uses.
This is more like a xerox than not - you can certainly violate copyright with a xerox. But the existence of the xerox itself isn’t to violate copyright. It’s for other purposes. The ambiguity obviously comes in that a xerox machine wasn’t built by scanning all documents on earth first. But I think the very act of mixing all the other images and documents together into the model, which again, is just a statistical aggregate of everything that was trained with mushed together, turns it into at worst a derived work that falls under fair use.
If you ask a VFX artist to create the "Superman Logo" with Photoshop they'll do an excellent job.
The first one isn't copyright violation because it is fair use. The second maybe if it is redistributed but we don't ban the use of photoshop by artists because they can choose to reproduce copyright things with it.
"It must have a copy" - but van Gogh didn't make paintings of hot rods or whatever, and you can't copyright style or technique.
You wont find a copy of a plaintext in a cyphertext. But you can still extract the plaintext from the cyphertext.