They said that the Navy became more aggressive and grew stronger in the 2y time skip, I think that we're about to witness something, like the Revolutionary bring owned in Mary Geoise and the successful hunt of the Schichibukai.
Then, after the Yonkou's fall, other pirates will conquer their territories but so will do the Marines.
That's my view, anyway I don't think that the marines is the beginning and the end of all of it like we beleived until the discovery of CP0, Imu and stuff, Marines are just a mean in the real ruler's hands and Sakazuki is just the Fleet Admiral, he will shine in his next move in the new world and in the final war but is confined to failure, because his view of Justice must fall by definition