Are you sure about this? I just checked coinmarketcap, and they are saying that the 24-hour trade volume for Bitcoin Cash is somewhere around $2 billion, which happens to be at least four times higher than the net worth of their one million BCH coins. I agree that dumping all those coins at once may be a very bad idea. But it is possible that they could sell at least 25-30K coins per day and complete the process within one month without crashing the exchange rate for BCH?
That 2 billion is churn largely on exchanges that are faking volume still.
It's not the concerted selling of real coins. That's a vast amount of extra selling pressure with no buying back. A whole month of it would flatten BCH completely.
Though I still don't really believe it some say the Gox liquidator selling on market was one of the prime factors in Bitcoin's fall 2018 and that was only about 50,000 coins.
I would agree. As per Coinmarketcap, the largest exchanges in terms of BCH volumes are OEX ($327 million per day), CoinBene ($294 million), LBank ($134 million) and OKEx ($84 million). And none of them have BCH vs fiat trades enabled. All this volume is either for BCH vs USDT trade or BCH vs BTC trade, which can be inflated as much as they like.