It's an awesome contingency. If the island falls, they can destroy/impair the local infrastructure, and reconstitute it in the US. Destroy in this context does not mean mass physical destruction. It is a combination of removal of keys and select components. The message being you can have the island but not the business.
And? Advanced nodes aren't really relevant to subtracting where it is from where it isn't. China is ideologically motivated to conquer Taiwan not economically.
In any event it appears that reunification is essentially inevitable and the only question is when. China doesn’t appear to feel especial urgency about it.