User blog comment:AYET/The worth of the Shichibukai to the Marines/@comment-4889755-20130529120347

I'm guessing Akainu has planned for Shichibukai betrayal since two years ago when they saw what was probably the biggest betrayal of a Shichibukai by Blackbeard, who went on to be Yonko.

I also think that he'd want to only keep Shichibukai that he could trust, meaning Law or Hancock could be facing having their title revoked. But there's also the possibility that he is threatening the less-trusted ones. Like if they were to betray the WG, Akainu would send a fleet to blow up their hometown or something of the like.