These predictions were made back in 2020. Now it’s already 2024, but nothing bad is happening with the currencies you specified and I’m sure that it won’t happen. In order for the currencies of these states to disappear, it is necessary that these states themselves disappear or they unite following the example of the European Union. Now almost all states and their currencies are going through difficult times. But this does not mean that they or their currencies will disappear soon.
If there is something bad that happened to them, that is their value had decline a little which is still normal and every other currencies experience that too. Indeed that currencies that he mentioned are way too huge for them to disappear. You already said a proper reason if in case it occurs for real. But again, I think it was still unlikely since they are also a big and strong country. Maybe if we are talking about smaller countries and currencies, yes.
For now, we have more chance seeing it on a new and weak crypto. But some don't disappear completely. Instead, they recover and pump huge for a while. This is why many people are here or prefers them over the traditional currencies because they think it's an easy way for them to get rich.