Milo,
With the B off probation and already being delivered to the USMC this will not happen. Commandant Marine Corps is a huge supporter and the Marines punch above their weight in political lobbying.
Harry,
re: CNO's recent comments. Have you checked on CNOs background? Career submariner so not surprising he advocates advanced sub launched weapons delivery over carrier borne aircraft. The C variant was always due to be the last of the 3 variants to come into service, the classic C/D Hornet is running out of life and X-47 is well behind F-35 in flight test so the USN need it. They don't need it as quickly as we do though (due to Super Hornet), so that was part of the UK return to B decision
USMC and USAF have already started taking delivery of OCU jets at Eglin with more arriving on a regular basis. Building of facilities at several MCAS and AFB sites is well advanced. That's a lot of money and jobs to throw away. Economies of scale come into play, if one variant goes the others become too expensive and the whole thing falls flat. USN,USMC and USAF may not like being so tied together but that's the way it is.