Claims you saw are not supported by official U.S. government policy. They are part of political argument from country that wants to challenge U.S. dollar global power. Idea that U.S. would use stablecoins or gold to devalue its debt is not standard economic concept. In reality recent laws in U.S  like GENIUS Act are designed to do opposite they make sure stablecoins are backed by U.S. dollars and government debt which actually helps strengthen U.S. dollar position not weaken it I think.