@Count:
Something like that's what I figured for a while, but it would be very weird if everybody in the family freaks out accept the small circle of oldest children who only respond with "lol Wait, you guys didn't know?" And I don't see any implications of the family respecting each other to the utmost degree without discrimination given Pudding's bullying from her siblings (which were much younger than Katakuri, I know) and her own mother. Daifuku even swats away Pudding for failing her assassination attempt.
This all just goes to show that I think the discrimination aspect in Whole Cake Island could have been done a lot better if there was more focus on the hypocritical aesthetic of Totland's racial harmony rather than focusing mostly on the wedding business so much. These occasional tidbits with Pudding and Katakuri having tragic flashbacks come across as being more awkward than poetic without more context of how discrimination can be applied to even the most trivial of traits in real life.
Not quite. The discrimination seems random however it looks like the discrimination in Tottoland is based on ridicule for those who exhibit traits unlike those of the residents of Tottoland. So it's mostly just weird deformities, however racism is still used in Tottoland against those whose race doesn't reside in Tottoland. This is why Pudding is bullied. Also unlike in most other kingdoms bullying is still carried out on royalty. In fact it appears that bullying overall is encouraged, especially when in groups. The family is weird cuz they don't seem to care for each other much at times, but then they're all don't hurt my siblings. Even Flambe who doesn't seem to care about anything but herself was dying for recognition from Katakuri and even valued the recognition of all her other brothers as sort of a compensation for not having Katakuri's.
=D