China is not stupid like America. In a hot war, it’s not going to needlessly open too many fronts against too many opponents.
If China is to invade and subjugate any other country as spillover from AR, it will be Japan. The Russians will probably be happy to split the tab and the country afterwards with China. They always wanted themselves a war water pacific naval base after all.
Say what you will of China’s leaders, they are not afraid to think big. The Philippines is a meaningless distraction in comparison.
I think the following assumptions are pretty reliable:
If no one intervenes then China is only interested in taking back Taiwan.
If US intervenes then China will attack intervening US forces, relevant bases, and may take over the Ryukyus.
If Japan intervenes then China will attack intervening Japan forces, relevant bases, and may take over the Ryukyus.
If the Philippines intervenes then China will attack intervening Philippines forces, relevant bases, and may take over SCS islands/shoals claimed by China but occupied by the Philippines.
China is not interested in occupying any part of any of the main islands of Japan or the Philippines or any part of the US.