There's two main factors about K-Pop which sadly means shit like this can pass through a filter.
1. They don't choose their own clothing, especially when they're as famous as TWICE.
2. Most of the idols will go to Multi-Art "schools". These places are there for rich idols to legally circumvent having to go to school while keeping up with an idol schedule. You learn absolutely nothing, you don't actually go to class, and you receive super easy "homework" to pass your grades. Chaeyoung has been at a school like this since Middle School and she's been in training since she was a little girl.
It's why a lot of people keep getting angry at idols debuting younger and younger, the honest truth is that a lot of them just have elementary or middle school educations at best and it shows.
That said, I'm still side-eyeing the ignorance of her and her stylist for the swastika. I've known about shit like that since Elementary but assuming she's redpilled is stupid.
So why are we giving an adult woman the benefit of the doubt after she already had to apologize for a Q Anon shirt?
Seriously, those are two very curious coincidences
I know for some people it's insane to believe that other countries don't know everything about America but this can happen. :P
The swastika one was very stupid, yes, but expecting everyone who doesn't live in the US to know what that Q shirt stands for is unrealistic.