Looks like the BRICS initiative is building towards this with an August announcement. But until it happens, this is still in rumor territory.

https://bmg-group.com/russia-confirms-brics-will-create-gold...

I don't understand why gold-backing is required. I'm a novice.

My understanding is that a reserve currency requires fluid markets and a stable, reliable, metrics-based currency policy. It's why the Fed is so stubborn about its relatively simple policy goals: 2% inflation and low unemployment.

Who stores the gold? Who audits the gold? Who trusts the audits? It isn't hard to wrap gold around tungsten.