I think its gonna be rather weak explanation, im asking myself that since wano
My only explanation so far, or rather what i think oda will say:
The only people that are strong enough to reach loadstar (given you must travel a chain of islands in the new world) are the Emperors and given everyone of them knows you cant reach laugh tale without the load poneglyphs they dont bother/camp in their territories
Which obviously doesn't apply to Luffy as a) he is not a camper b) he wants to visit islands just for the fun of it
Could be
Depending if we get out of elbaf chapters towards the end of the year could even mean some one else, like in egghead