The "D." is more than enough "chosen ones" shenanigan.
Stacking long lost joyboy's power, CoC, Nika, etc, that's when it becomes a problem.
I'm not a "tension junkie" that NEEDS main characters dying to keep me on the edge, but the problem I have with these prophecy stacking is that it reduces the sense of a vast world One Piece had.
I think the last time Oda did it right was with the Supernovas introduction. Characters that were having adventures of their own at the same time the main cast.
Now it all revolves around Luffy.
Even the Supernovas.
It's boring.