More importantly: “Who is buying” these treasuries and why? The fed is having trouble finding buyers for new and rolled over US Govt debt at recent auctions leaving the Fed and prime banks as the only buyers. That is the real reason that the Fed has been raising interest rates paid on new debt. I doubt that the Fed and its member banks are buying back foreign treasuries under these circumstances (unless the debt has matured and is being redeemed). Given the high demand for dollars to repay foreign debt, I doubt that the foreign US treasuries are being sold a steep discounts (i.e. at a loss) to be used for repayment. This leads me to believe that there are not sufficient buyers of foreign debt to absorb this amount of US treasury dumping. I suspect that something else is being done with these treasuries. My best guess is that the BRICS are using the debt to finance BRI construction initiatives rather than dumping the US treasury bonds on the market.
Besides ever since Trump signed FASB-56 in 2017, dumping treasuries on American soil will not show up in everyday economy. As CAF says " US dollar dangerous and dominant" above all.