alt Hacker News> it is assumed that we could be issuing public foreign debt in foreign currency.
That isn't how it works. You issue bonds, denominated in your own currency, and promise to pay the bearer of the bonds a coupon (interest) and repay the full amount (in USD) at the end of the bonds life.
Unless I misunderstood what you're saying.
There are multiple structures for foreign debt instruments, of which your definition is one. Even using your example, the "(in USD)" is the part that might change if USD falls out of favor as the context of this chain is discussing.