Not to mention that the main reason that Piltdown man was suspected of being fraudulent was that it conflicted with the predictions of evolution, not that it in any way demonstrated that creationism was correct.
Yes, many in the early 1900's were suspicious and it became largely ignored. It was NEVER a basis for supporting evolutionary theory so the determination that it was a fraud has no impact, other than to say that science worked.
Creationists did not work refuting Piltdown. As many (if not all) Creationists reject both radioactive dating and evolutionary theory, it's not evident what basis they have for such a rejection.