If China really is a socialist country or one pushing towards communism, why do you think they are waiting to push more directly in that direction? What is to be strategically gained from capitalizing your economy, essentially going backwards for 50 years instead of continuing to push for communism?
I get that you mean well but I don't think this is a good way to answer OP's question. People want to know how this leads to the eventual abolishment of capital or the commodity form. People don't want communist supremacy under an ostensibly capitalist system, they want communism. They want communities of people that love and care for one another, a global brotherhood of mankind, and they want all the evils of wealth obsession and commodification to go away.
"Communist supremacy" strikes me as language that will particularly get a rise out of people and confirm all their pre-existing concerns.
Don't get me wrong, I am not against supporting China, I just think there's a very different rhetorical argument needed and that this will not cut through to any fence sitter, let alone anyone currently against it.