Bitcoin can't become a global reserve asset like gold unless it's backed by rich countries. El Salvador's a small country it's decisions don't affect other countries. If BRICS G8 or G20 want to make bitcoin a global asset it's possible.
There's always possibility, if US approved BTC as strategic reserve, what's stopping other countries from reconsidering it?
I'm pretty sure even large companies are already reconsidering bitcoin for an investment, It's also 5th biggest asset in the world surpassing silver.
Even the chance for bitcoin to be used as a global reserve asset is quite big from this alone.