Britain lost their carrier aviation capability when they retired their Harrier force last year. Next decade, when they build a new larger carrier with a catapult to fly our new F-35s, they'll rebuild that capability.
We will help them since it would be impossible for Britain to retain the skills needed in that gap of time to operate the carrier. Indeed, Britain lost the skills for catapult-assisted air operations quite some time ago (even though they invented the concept).
And in the meantime, closer cooperation with France will allow Britain to have access to France's one carrier, if needed.
Nice theory.
In practice, I hope Britain doesn't really need to borrow France's carrier.
And in a decade, I sure hope the British will decide to spend the money to recreate a capability that they may think they've gone a decade without yet experienced no harm.
Promises to spend more money on defense in ten years when someone else has to come up with the money don't impress me. That's my ten year rule.