El Reg has more details on how Britain's new aircraft carriers ended up sans EMALS.
Consequences for Britain: inability to populate those new ships with any jets other than the F-35B. Apart from being insanely complex, and expensive to acquire and maintain, and sacrificing payload for the STOVL feature... apparently it won't actually be available for putting on those ships for a decade yet. Which kinda makes those expensive new carriers less than useful.
Consequences for me: as a sub-sub-sub-subcontractor on that EMALS thingy, I lose maybe $5K in anticipated work building two copies of an accessory.
And all because the prime shipbuilding contractor interpreted "should be designed to allow retrofitting with catapult and arresting gear" as meaning "... yeah, if you don't mind tearing the whole ship apart and rebuilding it from the keel up."