You seem to either be not understanding or misreading what I am saying. Granted it may temper some of China's demand, or it may not, we have no idea what China's demand will be in 2020. However the likelyhood of China placing extra oil on the market is far smaller than it is for the United States. As far as we know China could be in the mist of a recession by then, and could just store the oil for when the demand rises again instead of placing it on the market and allowing it to impact the global price of oil.
The fact is that by sending it to China the likelyhood that it will go onto the global market even by it's excess, to impact the price of oil, is remarkably low.