In Chapter 598 during the chat between Nami and the Bartender, where he told her about the change the marines have done between HQ and G1; He mentioned that the change was due because the new Fleet Admiral (whoever he may be?) wanted to be closer to the 4 Yonku ( Whitebeard, Big Mom, Kaiedu, and Shanks) [please excuse my bad spelling].
However even after the death of Whitebeard which was announcet at the end of the war. Therfore has someone else risen to take away his title, maybe Blackbeard or maybe even Kid, time will tell.
i just thought it was an interesting topic tell me what u guys think about it?