Sorry! I got a phone call halfway through writing that comment and just kind of trailed off there... (and then forgot about).
My point was that the CCP wasn't trying to make money from this adventure, they were trying to discredit the Bitcoin network because they are an authoritarian government and want as much control as possible over the movement of value of it's citizens, ie, WeChat.
I misspoke when I said everyone would be worried that their funds are next.. I should have actually said something like "everyone is worried the perpetrators could double-spend as much as they like". The initial 0.5 BTC was just to show the network that it could be done, to undermine faith in the network, not to actually steal or extract any value. Keeping it a secret would basically aim to confuse everyone who doesn't initially know who, what or why the double-spend happened to inspire a bank run.
In this hypothetical the CCP isn't trying to make money at all, they're trying to undermine the integrity of Bitcoin and its decentralized nature.