In essence detecting which one is fake is a common way how you train the generator, tweaking the generating process to "fix" any detectable flaw; and you train it until (as far as your system is concerned) the generated texts are indistinguishable from the real ones. A better system might distinguish them, but that better system can be relatively trivially adapted to generate better texts which it won't be able to distinguish from real ones.
GANs work by feeding back the mistakes and forcing the generator model to improve its cheating. In this case, filtering out titles that are ambiguous would act as an independent filter.