The RAF will own JCA (currently F-35C).
The RAF sacrificed Harrier and GR4 replacement (DPOC) in SDSR. The future construct would appear to be solely Typhoon and JCA.
FB11 makes a telling suggestion on the GR9 bargain sale thread - that Tornado (since SDSR) has become more expensive by £1 billion.
Whether or not this is correct a reversion to the B would appear to offer a lower work load to the Aircraft Carrier Alliance, another chance to balance the books for MoD, a strengthening argument for the RAF to man JCA entirely and not much to either the RN or UK CEPP.