Never heard that and don't believe there's any truth to that idea. Maybe there could be an issue on something somewhere but there are many more important things to worry about.

All of my plants are in different stages of flowering right now, and I am doing some experiments with increased fertilizers. Mainly 202020, and ammonia sulfate crystals. One of the members was mentioning using a lot of nitrogen can cause citrus buds to fall off. I noticed a lot of my BLueberry flowers are coming off, bit hard to tell if it's natural.