A requirement of "AT LEAST" 8GB doesn't mean you will have an enjoyable experience at 8GB, only that the developers deem 8GB to be the minimum realistically necessary for the game to probably run without game-breaking issues as long as you don't have any major other stuff open at the same time.There are still AAA games out with system requirements at least 8GB RAM.
While you can play WoW and many other large games on 8GB of RAM, most are far more enjoyable with 16GB to greatly reduce asset streaming hiccups and loading screen times. Easily worth the extra ~$30 if laptop and PC manufacturers decided to make 16GB the baseline for ~$10 extra profit or $50 if the laptop's memory can be swapped out with an aftermarket kit.