It's not just gold that's being accumulated by non US banks, crypto is also starting to get accumulated. You're right on the money when you say that the dollar is on its way out as the reserve currency. The countries moving away from the dollar are all trying to lessen the blow for when that happens. It will be a a big hit for everyone seeing how much of the world is tied to the dollar. Gold seems like the best bet, but no one really knows what will take its place, which is why you're seeing many investments outside of just gold. I like to think that this would be an excellent opportunity for crypto to try to step up to the plate but as of right now, I dont think there is any project that is ready. That said i'm still a big fan of monero and believe in the project.
No country is buying any crypto right now. Best chances is the crypto they get from some busted illegal operations. Specially in countries where court system is slow and takes years and years and years until trials gets finished. Some such countries will get rich not even knowing they did.
There was a report of Russia starting to buy Bitcoin, but who knows if it is even true.
https://www.telegraph.co.uk/technology/2019/01/14/russia-plans-tackle-us-sanctions-bitcoin-investment-says-kremlin/
Fake news.
Trump lover