This is a very good definition, but today people will just claim the AI is not a victim, and pass this argument off to the legal cases the labs are already having in court wrt fair use. It's sad, but this is the argument people have made to themselves.
The ‘real author’ isn’t the only injured party.
Copying from a book with a long dead author, or paying a willing confederate to write your thesis for you, is still plagiarism.