I didn't take Newspeak as a serious philosophical contribution so much as the propaganda of Big Brother, and I didn't quite understand your gloss of it either. If you mean that emperors are virtually slaves to the many and thus share with actual slaves an understanding of duty and self-denial, OK.
That was exactly my suggestion, an Emperor possessed of a strict moral conscience is totally unfree, he is morally obliged to take care of the peoples of the Empire, Marcus Aurelius's charachter particularly fitted him for this burden. I was also thinking of those people in modern society who prefer "institutionalised" or ritualised living in preference to active citizenship as an example of "willing" slavery. I dont suggest Orwell as a philosopher , but his work resonates profoundly to British Libertines.