The Freakonomics thing is more complex than that though.
It points out how upper classes aren't held to the same rules. And this doesn't affect their education.
Indeed there's a pattern of the upper classes adopting a weird name, it being copied becoming popular and then becoming regarded as unspeakably awful by the middle classes in the UK. Best example I can think of off the top of my head is 'Harper'.
In 2011 43 girls were born with the name. Then a certain Beckham had a daughter, and just a few years later in 2018 over 1500 girls were named Harper and in 2023 it was the 22nd most popular name. Normally names gradually increase in popularity and you can see a general trend. Harper is unusual because it came from nowhere and no one saw it's popularity coming.
It's actually a nice name, which doesn't have a crazy spelling - and that's why it's gone nuts. But it'll be regarded as chavvy soon enough due to the above association.
Going back to Freakonomics, it says an unusual name CAN be a hindrance but it can also be to your advantage too. The CV with the unusual name to make it stand out from the crowd and is memorable. It's a really fine line between getting it spot on (which arguably Harper did) and just being plain weird.
The whole argument is a complex one and it's not as straightforward as many make out.
Freakonomics also argue about causation and correlation. Lots. Lots and lots. The point about causation and correlation is one of Freakonomics core repeated points but it never fails to amaze me how many people miss this.
Low attaining parents are in a different cultural bubble and are more likely to have low attaining children cos genetics. You can't discount this.
There's a whole host of things about how a name can inspire and perhaps unwittingly influence someone too.
Then there's the psychology of having a dull as fuck name and becoming the wallpaper (and how you might kick back against that when you have your own children)
You have to read what they say on names multiple times - some of it is really contradictory.
(Guess who read it a lot about names whilst pregnant... It hit me just how significant a name is. It's not just a name - it potentially is a gift/curse.)