The world government has several intelligence agencies and we met one of them during the Enies lobby saga. CP9 was the strongest of the Cipher Pols, with the exception of the 0 Aegis Special Division. And in the latter, characters like Rob Lucci and Kaku went through. Luffy and the others then find ONE PIECE's old enemies.
This is because CP0 is also present in Onigashima. After the first appearance in Dressrosa and the following in Wano, the trio of masked agents followed the war between the samurai and Kaido pirates in an adjoining room, amazed at the consequences. But chapter 1028 of ONE PIECE put the cards back on the table with one move by Rob Lucci who, by order of the world government, will lock Wano in his hands and bring him under his control.
The arrival of Rob Lucci and the ships of world government will therefore force the Mugiwara to face other enemies as if the war against Big Mom and Kaido of the Hundred Beasts wasn't enough. It will therefore another fight that will inevitably prolong the Wano saga even further, maybe with a fourth act. In the future, will we see Luffy VS Rob Lucci or will someone intervene to suppress the ambitions of world government and thus enable Wano to find his final and longed-for freedom for years?