That's why some might cash out into USD. Either directly, or via BTC. Zero reason to be stuck in BTC.
That said, "rich people" don't store their wealth in fiat money. Because it's stupid, that's not what money's for. Rich people who think that keeping their money in a mattress is smart become poor people, with or without 0.5% yuan depreciation.
Sometimes keeping your usd in a mattress is a wiser choice that risking it in some risky investment. If your goal is to store your money and not increase your saving, just use fucking saving account, which are like mattress.
Devaluation of yuan rel. USD & USD becoming weak rel. yuan are mutually exclusive.
Try logic.
Idk if you are not understanding his words on purpose, but is is written USD rel. Eur or franc swiss. American would be in a much better situation with a weak dollars vs euros regarding the huge amount of stuff that they export there...