Not necessarily so, ORAC. The RN CVF design has always had the option to fit catapults and arrester gear, so the C is not ruled out as an option for the RN if this was to happen.
ISD might be affected a tad, of course, but then again maybe not since development of the STOVL variant was always likely to be the trickiest of all options. The CV variant may well have a reduced development period c.f. the B, I'd guess.