The US should be dragged to the ICC, just because the US commits war crimes that greatly harm civilians doesn’t mean China should do the same. China should aim to be more moral than the US not the extact same. Without power stations or fuel, water stops pumping, so they’re now drinking dirty water, food stops becoming refreshed spoiling food, hospitals stop functioning. All of that is what will happen if you destroy every power station and fuel depot it’s a massive war crime and I doubt China wants to cause mass harm to civilians just to reunite with Taiwan especially when doing this will destroy almost everyone’s support for China on the island.
As I've said previously, I expect Chinese ships to be on standby to deliver aid such as food and petrol for humanitarian purposes.
Of course, that assumes the DPP allows this to happen. It may be that the DPP refuses, but then, you can't blame mainland China for that.