The WCI Road Poneglyph sticks out like a sore thumb. The other 3 are/were at located at very historically significant locations that were allied with Joyboy. One is on Zunisha, one is in Wano, and one was in Fishman Island. Before Big Mom came along, WCI was an irrelevant, remote island which wasn’t even called WCI at the time. WCI was the island where BM ate Carmel and the orphans, and it only became WCI after BM and Streusen terraformed it with their powers. Why would a RP be on a random island, and if it was there all along, why was it not taken by the WG already?
It makes far more sense that a RP would be on Elbaf, one of the most significant islands in the world and probably Joyboy’s strongest allied nation. If I recall correctly, it was mentioned earlier in the arc that BM returned to Elbaf at some point, and we know from Goldberg’s shield being a Homie that the Giants fought with adult BM at some point. Perhaps BM stole their RP when she returned to Elbaf? Her fire and lightning powers would make attacking Elbaf relatively easy for her
It makes far more sense that a RP would be on Elbaf, one of the most significant islands in the world and probably Joyboy’s strongest allied nation. If I recall correctly, it was mentioned earlier in the arc that BM returned to Elbaf at some point, and we know from Goldberg’s shield being a Homie that the Giants fought with adult BM at some point. Perhaps BM stole their RP when she returned to Elbaf? Her fire and lightning powers would make attacking Elbaf relatively easy for her