sounds like Chinese superstition to me.

Keep in mind that gunpowder teas can be the strongest of the greens and are
very sensitive to steep time and amount of tea in the pot. Too much of
either and you will have a very astringent, harsh tasting brew. For this
reason many people do not like it. I like it but have had to pour out
plenty of pots because I got the steep time/amount wrong. Gunpowder is the
hardest tea to get "right" in steeping. Do not judge all greens by
gunpowder because it's very different from most.