As per the statistics "Satoshi Nakamoto" mined around 1 million bitcoins in the early stages. So, he has gotten the same quantity of BCH as well.
What will happen if someday he might see his project at risk of overtaken by Bitcoin Cash. Could he be dump his BCH stake anytime?
Personally, I suspect that he burned a lot of the early coins. People speculate with similar fearmongering about him dumping his BTC on the markets, too. I think if any of the early BCH moved that both the BTC and BCH markets would be spooked. But I think that's highly unlikely due to Satoshi's past actions; he never emerged when past fork threats came about. Why would he do so now?
I think he knows that if the design requires an early miner like him to destroy competitors with market supply, that the design has failed.