That article is about oems selling in china. And it doesn't account for all of the various subsidies including battery production and other suppliers and raw materials. They also inflate sales with artificial demand which lowers unit costs. When 35% of your income comes from the gov't that's huge.
Selling in China is one thing. Selling in foreign countries is entirely different and nothing is stopping the chinese govt from doing more subsidies on top of what they were already given.
That's not to say they don't have cost benefits from other things as mentioned, but that is clearly not the entire picture.