I'm thinking.. Gol probably took luffy's path, seeing as how skypiea was considered PART of luffy's route by the log pose, and how gol left his writings in there. not to mention the increasing numbers of people along this route showing their knowing of gol personally.
i certainly don't see any point in gol returning to the grand line and taking another route, i mean why go through months of travelling again? if he made it through the GL all the way to raftel, it's probably just one line imho, a line he got familiar with.
doesn't this mean at any point in the story, luffy travelling down this (according to my theory) same route as gol did could prove to be a big part of the storyline of OP? like discovering things bit by bit as he went through the islands, and only realising how they linked up some time in the future
any theories/followups?