It isn’t changing. Look at foreign reserve holdings for the US since the 90s and you’ll see it’s decreased by a total of 2% and is still over 2/3s of all of it. What happened was that during the run-up to Covid the US dollar spiked to nearly 3/4 of all global reserves and has since dipped back down to normal levels.
The libertarians keep saying this. Yet the US continues to sell bonds to international investors who never question if the credit line is overextended. They continue to use the economic model they learned in high school economics class to a more complex economic model that is designed by and for a hegemony.
The US has an almost unlimited credit line because investors are clamoring for it. It's literally the best, most stable investment going right now. They wanted it to be the EU and it has not been. They wanted it to be BRICs and that is a flaming dumpster fire right now. Very soon, they will state Africa is a better bet than the US. It's a young, dynamic economy; the very opposite of stable.
The US debt is $32.3 trillion, and skyrocketing. [1] Total debt held by foreign/international investors is $7.3 trillion, and declining (both in absolute $ as well as percent). [2] The largest single holder is the Federal Reserve. Other holders are disproportionately made up of domestic organizations (like pension or mutual funds) which will collapse when the USD collapses, essentially regardless of hedging efforts, so they have no motivation to consider risk of collapse in their evaluations.