And first day strike against who? Not China, or anyone else equipped with a decent ASW missile keeping the carrier more than 250nm offshore, at least not until the MQ-25 reaches the fleet in operational numbers, which is many years away. And if they intend to use stand-off Mx, then the current generations can’t be fitted in the weapons bay so have to be hung under the wing, so you might as well use the existing F-18s.
But back to the point that the Super Hornet purchases to date, and planned, have already replaced all the USN aircraft planned to be replaced by the F-35C, and the now funded life/capability upgrades will keep them in the fleet until around 2030-2035, when the FA-XX is planned to start entering service.
As I said above, the money’s been spent, the manpower assigned and the decks full. Hell, you can’t even lend them to the RN for the UK carriers.....
And as you say, the F35C that have not yet been bought...