I used to have the official Kinder Surprise Egg Advent Calenders when I was little, but they sadly stopped selling those - and replaced them with gendered ones, which I refuse to support.
I'm not a Kinder egg person, but I noticed the eggs being separated into blue and pink too. Superheroes in one and princesses in the other. Weird move but maybe it makes business easier. Doesn't affect me.
I have one that has a different gemstone in it for every day. It's really cute!