I don’t know how Oda will play out the next couple of chapters but it will definitely be critical for the continuance of the series fandom to back as many have said, it could be rather disappointing if Luffy is some ‘chosen one’ and has this mystical power that backs him up no matter what (I.e Naruto having the nine tails save him every time something difficult came up). I hope Oda manages to play this correctly.
As for what we’re seeing, I feel like Oda is connecting this to inherited will yet again. Here is my theory
Joy Boy is not someone. It’s a will. I feel like Nika the Sun God was from the ancient kingdom and something happened between him and the current world government which brought to slavery and destruction. Nika was also known as Joy Boy for his endeavors. He passed on his will in some form or another. When Zunesha says he hears the drum of liberation and says that ‘Joy Boy is back’ he is in fact referring to Luffy being the man that is rising up to the challenge and taking upon himself what Nika the Sun God once stood for. This also directly connects to the lantern wishes we saw last chapter.