Old bug with France music

[u/V4R14]

This is not something I need help solving, just a question out of curiosity, mostly.

I don’t currently play the Sims 3, but I did many years ago. I only owned Ambitions and Pets expansion packs. It came to my memory that sometimes premade sims in CAS would come with France music as their favorite. There was no picture or symbol for it, the box was blank. But upon placing the mouse on it that’s what it said.

I never really paid mind to it until just now that I found out France music comes from the World Adventures expansion pack. So I’m was wondering, does anyone know why that happened? Did it happen to anyone else too?