This is hilariously a
result of China's view. China's claim is that Taiwan is part of the still civil warring China, and should be re-integrated. Part of that strategy is an insistence that OTHER countries need to parrot this claim, including countries like the US that recognize Taiwan as an independent entity. The "oneness" of China is vitally important.
The claimed story is that Taiwan is worried if they abandon the "one warring China" policy and openly state they are Independent, that will aggravate China and cause them to push their claim harder, and maybe lead to war.
Taiwan having such a policy is directly because that's the policy China wants everyone else to claim. Notably, Taiwan has taken zero effort to produce a military capable of doing any over-water invasions, which would be absolutely necessary if they actually wanted to do that. Unless you think Taiwan would rely on the USA to invade China for it, which I do not think the US ever wants to do. Our explicit strategy is to own all the islands around China (including Taiwan) and basically blockade China in all but name.
China meanwhile DOES build a military to take over Taiwan, explicitly, including systems designed to sink our carriers and practice targets in the desert. Strictly speaking I'm not concerned about China wanting a viable means to sink our Navy, as China doesn't want to starve to death if we could blockade them, but the buildup around the capability to take Taiwan betrays that it is not a defensive posture.