Crippled Russia plays in to China`s cards as well. Russia is going to be at mercy of China if Putin stays in power after this war. Which is most likely unless there is massive revolution in Russia.
Russia isn't going for democratic revolution as people just aren't capable of it. Russia is kept together by the strong centralized power. Once that power gets critically wounded (like 30+ years ago USSR by Afghanistan) the regional, especially in the far from Moscow regions like the mentioned Khabarovsk, elites will try to split out to have their own autocratic dukedoms, and naturally becoming China's client states.
China's support of that Russian war is a non-loosing bet - if Russia succeeded China would have gotten the agreed upon Russian support of the Taiwan takeover, and if Russia loses, especially catastrophically like it looks now, it gets very weak and sky is the limits for China's actions in that scenario.
Doubtful, given the state of the global economy.
And in the meantime, China became the United States' largest source of imported goods and 3rd largest export target (or 4th largest if you count the EU as a single block).