TSMC machines have kill switches built in for such an event. https://www.datacenterdynamics.com/en/news/asml-adds-remote-...

Sure, but I'm imagining a situation where China ensures the ongoing operations of TSMC via negotation with TSMC and the Trump government, to the satisfaction of all parties, and then being 'allowed' to take Tiawan as a result. For example, they could allow TSMC to function as an American-run entity for a number of years, or offer US companies very friendly terms, or something similar.

This doesn't account for the actions of Tiawanese nationalists working in TSMC setting off the kill routine themselves, irrespective of the deal struck, but it's still an interesting scenario.