On Joyboy: The Destiny and Undestiny of Monkey D Luffy

Freedom is the main theme at the heart of One Piece...Or is it? Has it been contradicted by the themes of destiny? (*Taking a look at the unpopular theory of Luffy and Zoro being the reincarnations of Roger (or Joy Boy) and Ryuuma, and why it wouldn't even matter thematically, at this point, even if it were true.*)