For real though, i think Oda is on the path to establish the Warlords again as a Collection of Powerful Pirates, hence we finally start to get their "Real" Bounties.
And just like how we had all the 7 Warlords & Teach all participate in Marineford War, i think we might get a similar scenario at the Final War too.
Maybe the Warlords fighting & beating their respective Adult Seraphims at the final War? To show that the Copy will never be better than the Originals.