But, what can they get after this? To earn more profit? However, I think people will stop supporting BTC once they figured out that it is now fully centralized and China can only get a bad reputation which I'm sure they don't like for it to happen.
Controlling the network wouldn't yield any profit but if your enemy uses it as a reserve currency taking control would be catastrophic to them. If NATO or USA adopted bitcoin like el salvador then China would have a reason to take down bitcoin.