Why would they? The CCP isn’t stupid. They’ve put up with the situation for seventy years. They can wait a little longer as Taiwan’s protector loses all credibility as far as the guarantees that have kept the CCP off of Taiwan. The Taiwanese aren’t stupid either, they see their American guarantee is probably worse than useless. Most likely the DC guarantee would last long enough to get the war going before DC cuts and runs, leaving Taiwan to the tender mercies of a wartime CCP. Negotiate. Don’t be like Ukrainians and have the country destroyed while banking on DC promises. Just because DC said Taiwan is not China does not negate thousands of years of Chinese history.
You do not understand the people of Taiwan at all. That is why you misread everything about the situation.