That's not true, unless you think that Germany is not a "major nation". In 2019, Volkswagen, by far the largest carmaker in Europe, sold
as many cars in China as in Germany. If China decided to pay for imported cars in RMB only, what could Volkswagen do, stop selling cars in China? Of course not. The company would take the RMBs.
And Volkswagen would enjoy the RMBs: there would be so many things they could buy from China. When the BRI (which includes most of the countries in the world) becomes an RMB zone, Volkswagen will be able to buy even more things.
Similarly for Airbus. Would they refuse to sell 320neos to China and lose trillions of RMBs? I doubt it. As Airbus and Volkswagen go, so goes the rest of Germany.