Doublespeak here ought to be doublethink. The person who first defined it must have had doublethink confused with newspeak and thus combined the two. The definition given is for doublethink.
Whatever was true now was true from everlasting to everlasting. It was quie simple All that was needed was an unending series of victories over your own memmory. "Reality control," they called it; in Newspeak, "doublethink."