Their defense will be that it’s not perjury or conspiracy if they believe the BS.

IANAL but I believe that lying in an op-ed is not a criminal act. You can be sued in a civil action for publishing false information in any kind of article, but you cannot be criminally prosecuted for doing so. Whether or not a non criminal action resets the statute of limitations on any perjury or conspiracy charges in this case is something I don’t know.