.... the old fiat usd will be exchanged for the new currency and our bitcoins will be revalued in the new metals backed currency.
Nobody is going to revalue bitcoin other than 'we', the market.
There is a world outside the US.
We are already revaluing bitcoin every day and the inevitable scenario is already priced in partially.
The revaluation will happen, but again, we (and newcomers) will be the ones who will revalue bitcoin.
Spoiler alert: the price will moon.