Ok so in the last chapter Buggy received a message from the government
we have not yet seen what it says, but I am pretty sure it is offering him the title of Shichibukai. Think about it, The Shichibukai are dwindling. With Moria, Jimbei, Blackbeard, and possibly Boa (if smoker or Sentomaru rats her out) they need to fill their ranks. Not so much for actual power, they have pascifista for that, but to save face and intimidate.
Buggy to me is the perfect candidate. He has a crazily notorious reputation, an army of high bounty villains who follow his every word. To the majority of the world (who don't actually know him except through watching/ hearing about the war) he is probably an incredibly fearsome pirate.
While he wouldn't be of real use for suppressing real threats like the emperors or Dragon, to rookie scrubs, and low class pirates he would be a very useful deterrent.
Let's be real, the winds of the world aren't heading east or west, THEY ALL GO TO CAPTAIN BUGGY!!!!