Earlier quoted context omitted.
They can keep issuing them. They will not have the same value, though.
No this rule does not apply in the US. The US has printed 20% of all dollars ever existed since 2020. Check the exchange rates with any other currency, EUR, British sterling, Chinese RMB. Did it become cheaper? Of course not. We will always buy USD, because it has as a collateral 8billion lives.
Against everything else than other unlimited supply currencies, fiat money has fallen dramatically. It's a simple fact, not an endorsement of anything.
Everyone knows the basic mechanics of supply and demand on price, but somehow when it comes to fiat money, many manage to swap common sense with a number of convoluted theories.