How about when Sandys 1957 White Paper predicts the imminent end of manned combat aircraft the RNs carriers are re-rolled as strike carriers, specifically tasked with finding and destroying mobile ballistic missile launchers. As fighters are to be replaced with SAMs and ballistic missiles can destroy any fixed target, the sole missions requiring manned aircraft are the location and destruction of mobile ballistic missile platforms, be they TELs, surface ships, or submarines.
This anti ballistic missile launch platform mission has priority over all else which means as many carriers as possible are needed i.e. Albion and Bulwark are retained as carriers, new ships are designed and built, bringing the carrier fleet to ten (twice real world) and the Colossus class are converted into CVS to hunt SSGs, SSBs and SSBNs, the Sea Vixen is retired and replaced with multiple guided missile ships (converted and new destroyers and cruisers), Scimitar is rerolled as a strike platform and the Buccaneer is evolved into a ballistic missile launcher hunting TSR, while plans for a supersonic replacement are brought forward.
This changes the future structure of the RN such that they end up with a class of, smaller than CVA01, strike carriers, each operating two squadrons of Tornado fleet interceptors, another two squadrons of Tornado strike aircraft and a detachment of AEW, possibly E-2s and a pair of SAR helicopters. These are complemented by a much larger number of guided missile ships, including a class of Escort Cruiser (guided missile armed helicopter, command cruisers, resembling but smaller than the Invincible class light carriers), a class of gun / missile cruisers, as well as County class DLGs and a variety of new build and converted DDGs and FFGs.