Well, if Jihan and friends have their way, BCH will never have the most accumulated SHA256 work. They are hinting around that they want to decrease the block times to 1 minute and perhaps implement POS.
He's got plenty of hashpower on hand. It's only natural he'd be better off allocating as large a fraction as possible to the more valuable coin. Also, POS can be a very good thing. For those that hold the absolute majority of tokens, at least.
Of course POS would be a good thing for Jihan and his ~1,000,0000 BCH.

However, POS on a limited supply coin is always less secure than a POW coin. All an entity needs to do is accumulate 51% of the coins and be in a permanent attack position. No amount of competition will ever be able to unseat them.