first of all welcome to Wine Making Talk
The issue is dosage. We have many examples of people and animals consuming apple or peach or apricot seeds along with the fruit pulp with no harm. , ,,,, ie no farmer is concerned about feeding apple to the pigs in September, or we don’t see dead birds around elderberry bushes ,,, the dosage is limited by the caloric content of the fruit.
We have extremely rare examples of folks saving their apple seeds and roasting several cups of them, eating them straight like nuts and getting poisoned by cyanide.
Cyano-glycoside (?) is a natural molecule that the cells produce and in limited natural quantities the kidney will detoxify. Another common example would be the nicotine molecule (tobacco) which in the dosage humans get produces a relaxed mental state but was purified and sold as a natural/ use indoors plant insecticide.