Saying "Taiwan is in fact occupied by China" is at best a gross misrepresentation. It's like saying "North America is in fact occupied by Europe now [...] for North America to be free, in any proper sense, the European occupiers must leave." Well, maybe, from a certain point of view? But kind of pointless in terms of a realistic path forward.

We are not talking about remaking history here. We are talking about the present and the future of Taiwan. Its population and culture are what they are now.

Chiang Kai-shek's move to Taiwan and subsequent rule was indeed at times brutal, and the immigration massive in relative terms. But that move took place in the 1950s, and since that time amends have been made. You will see monuments and remembrance days related to those events. Taiwan is now a thriving (if at times feisty) democracy where minorities are protected.

During my last trip to Taiwan, I revisited the Chiang Kai-shek Memorial Hall.[1] What struck me is the museum underneath. Here, for all to contemplate, is a documentation of Chiang Kai-shek's life and rule. The striking part is that the errors and brutality of his rule are also well-documented and preserved, officially accessible to all. Try to find anything like this kind of recognition of past mistakes in mainland China (hint: you won't find it).

[1] https://en.wikipedia.org/wiki/Chiang_Kai-shek_Memorial_Hall