That would be as foolish as China launching a pre-emptive strike against the US.
People on these forums are far too quick to throw war around. They forget that war is only a beginning, not an end.
Let's say the US militarily strikes China, then what? What is their objective? China has a massive industrial capacity and far more territorial depth than the US military can ever hope to cover. An unprovoked strike at China would shred what remains of US credibility and influence, put massive strain on its already teetering economy, while China would go on the war footing and start churning out weapons at an astronomical rate. The US would end up suffering the same fate as Japan when it launched Pearl Harbor.
Clearly, the US is not planning to launch a pre-emptive attack on China. They are trying to shape global events in order to force a Chinese first strike against Taiwan, and then use its regional vassals (Japan, SK, Taiwan, Philippines, Australia) to bleed China dry while sitting safely back across the Pacific.
China's response to that strategy is simple: ignore the provocations and build up its defenses. The key point of contention here is whether a unilateral declaration of independence by Taiwan would force China to launch AR before it is militarily capable of defeating the US and its vassals decisively. I believe that is the fulcrum US strategists have latched onto, and indeed pinned all their hopes on, but it is nothing but wishful thinking. Regardless of when or whether Taiwan declares independence, China will launch AR when it is ready, and not a moment before. There are no material obstacles preventing China from taking this most rational and beneficial decision, therefore this is almost certainly what China would be doing in such an event.