Whitbeard has said to blackbeard he was not the person roger was waiting for ..
I no longer see it as 'you're not the one roger is waiting for'
it's joyboy who is the one that's waiting
this flashback has given us a few more pieces of the void century puzzle and I think joyboy didn't fulfill his promise or desires back then (the promise with the fishmen and poseidon, and whatever else he wanted to do) for whatever reason and so he has the poneglyphs created as not just a map but like a set of instructions (last
will and testament) to guide someone to laughtale and to help fulfil his wishes
I don't know what he left at laughtale but roger reached the place and due to his disease couldn't accomplish whatever it is joyboy wants so roger purposely hands himself in to the marines and sparks the golden age of piracy in the hope that out of all those that go out to sea someone will reach laughtale and be able to use whatever it is that joyboy left to achieve joyboys wishes
I don't think luffy is joyboy's reincarnation, maybe a descendent since I think joyboy is a D but luffy isn't joyboys rebirth in a new body
nor do I think that luffy specifically is the chosen one, whenever this new sovereign is mentioned by the seakings or as oden mentions this person will arrive it's always vague as to who it is, obviously we know it's luffy but the characters in the story don't know the exact place they'll be born or gender, joyboy and roger are likely believeing it'll be another D who is the one
anyway that's how I see it currently with all the pieces we've been given so far and as the story progresses we'll get more of the bigger picture
I just don't think it's the same as narutos 'chosen one/boy of prophecy' and 'asura reincarnation' plots