The Navy is seriously considering stationing the USS George H.W. Bush (under construction) at Mayport. If this carrier were assigned to the new Fourth Fleet...
It might be the fact that my caffeine levels haven't reached optimum, yet, but I'm not following you here. Why would assigning CVN 77 to Fourth Fleet be special? I'd assumed they would get a CVN anyway.
Carriers won't be permanently assigned to the 4th Fleet, just like they aren't permanently assigned to the 6th or 5th Fleets. They'll be detached from the 2nd Fleet and deployed to the 4th as necessary.