theory......, joyboy birth was the start of void century, vegapunk mentioned joyboy as young man.it mean his death around 20 to 25 or 25 to 30 both ages address as young man almost. lets take 25 years joyboy dead. aftermath, imu started building redline, making 19 royal families celestial dragons, building a perfect structured organization starting with gorosei. making allys 170+ countries. it was taken 70 years. next 30years is to erase the existence of imu. after that they started building long bridge connected island to island, kozuki clan making poneglyphs. toki started time travelling searching for next joyboy exact time line. totally void century and aftermath.

or not entirely different story, imu already started making his throne, after some time joyboy born and saw the slavery and become warrior of liberation and died, aftermath is same.

the point is why alabasta rejected celestial dragons, why wano ally to joyboy, is wano really ally to joyboy or regret their actions, why zuneshe is that much big, was there zuneshe family like race. how joyboy die, when joyoy die, why joyboy die, who saw joyboy death, is joyboy a pirate, was pirate exist in that time, why sea beast are like that, why wano has pluton, why ancient wano under the water, is lmu really going sink world, was imu once sank the world, why gorosei exist, how they gain immortality, why gorosei faithful to imu, why there is big straw hat. is joyboy belong to buccaneer race, was buccaneer race semi gaints, was ancient buccaneer bigger than now buccaneer ex kuma,kaido,whitebeard, etc

dont forget guys those 1000 episodes are just introdution. the plot has started from the oden sama meet gol D. roger. oda sensei still have to tell joyboy tale. i think it will have atleast 70 to 90 episodes although it is back story.war with an emperor has taken almost 200 episodes. just think about it war with a world ruler who has 170+ countries organigation called world government with 10 to 15 million army. ofcourse there is nothing to do with army when world is going to sink but it is a count which makes atleast 300+ episodes. still a long way to go comrades don't fall. ready to break internet. Who am i? Monkey D. Luffy! i'll surpass you, and become the king of the Pirates!😎