The Federal Reserve is not truly waiting for China to create a disaster for it, but rather for China to provide it with a narrative.

As long as external reductions, auction pressures, and term premium increases occur simultaneously, the Fed can expand its balance sheet again under the guise of "maintaining market function" and "supplementing reserves."
At that time, what it appears to buy is liquidity, but what it is actually supporting is the financing ceiling of the U.S. Treasury.
Ultimately, whether or not to cut interest rates is just a front-stage move; who will stabilize the back-end of the 38 trillion debt system is the real drama behind the scenes.