I am thinking that they eventually will have to monetize the physical metals for a replacement currency and that will restore confidence (at least for a few decades).

The problem here is all those dollars in foreign reserve accounts. If the dollar becomes convertible again why wouldn't foreign holders try to trade their dollars for gold to back their own currencies? It's more or less the same problem that led to closing the gold window back in 71, isn't it?
Under Breton Woods, the rest of the world pegged to the dollar which was pegged to gold. Why would they do that again after what happened the first time around? Wouldn't they rather hold gold instead?

ebear