We don’t know that yet. We know nothing of Joyboy except that he had the Nika fruit and lived 900-800 years ago. Is Sabo ace reincarnated just because they have the same fruit? No! Is Bartolomeo the old hag from Wano reincarnated? No! Chill guys let’s see where this goes and don’t compare one piece to Naruto, when they are nothing alike.