According to the Torygraph the decision is to scrap the F-35B order and buy the F-35C instead. In that context the USN training for the RN crews makes sense.
That does mean fitting Cat & Trap to the carriers, but the option is built in; it also allows for the option of buying Hawkeye AEW off the shelf, rather than a rotary AEW.
In the slightly longer term it opens the option of replacing the Tornado force with a smaller force of either F-35A or F-35C. with the radiply reducing commonality between the two models, and the flexibility of being able to cross train if and when required, then a future RAF F-35B would seem logical.
The Torygraph does seem to totally misunderstand the situation, however, as if they think the "cheaper" F-35C is somehow inferior - rather than superior in both range and payload.
Torygraph:
Jump jets to fall victim to spending cuts