Not quite, not eating pork was codified into those religions because breeding pigs in hot dry climate is a very bad idea. Same in India, a cow is far more valuable as a farming tool, so it was codified into religion. The Swan thing is pure aristocratic elitism. The guests invited to certain functions reported being served swan, and said it tasted like turkey.
And besides, British royals are Germans not Brits.
> And besides, British royals are Germans not Brits.
One's father's ancestry doesn't determine one's nationality. The majority of King Charles III's ancestry does appear to be German (about a quarter British, and a good helping of Polish), but Prince William is majority British.