Not everybody believes so, as you say.
https://qz.com/1518787/taiwans-indigenous-people-remind-xi-jinping-it-has-never-belonged-to-china/
None of this changes the fact that the so called “anti-communist” Taiwanese in Queens, NY and the San Gabriel valley are big time Dem voters and have been since the 90s. I guess keeping Taiwan in the current state prevents further immigration is the best thing out of this.