okay this chapter got me to think about the limits to the celestial dragons. if the world government took the nobles slaves due to the pardon with jinbe. that means that the world government does have power over the nobles they just dont limit their actions as long as they dont want to or have a reason for it
proof. the nobles have slaves. jinbei becomes a shichibukai and gets a pardon. the world government releases the slaves the nobles have. and they couldnt do anything.
in other words the world government or the gorosei can tell the world nobles " shut up nobody likes you".