Maybe, but China only holds about USD1T in US bonds. With the majority of that not maturing in the next four years.

China has fluctuated between being a net buyer and net seller recently (https://ticdata.treasury.gov/Publish/mfh.txt)

If China stops buying then they'll lose their competitive advantage compared to regional neighbours with the US.

when you have sovereign-nation-levels of wealth, there aren't many other sane places to park your money.

Have they made that threat?