>I assume "Taiwan region" is simply something to satisfy the PRC gov't (CCP) which believes Taiwan is a part of its country and governed by PRC.
To be fair, Taiwan (Officially the Republic of China) also claims that it is a part of China and is in fact the rightful rulers of China. The Kuomintang withdrew to Taiwan after losing control of mainland China to Mao and the Communists. I'm not super up to date on the latest claims between China and Taiwan, but Taiwan has never recognized officially that they do not rightfully control China.
To be fair, Taiwan (Officially the Republic of China) also claims that it is a part of China and is in fact the rightful rulers of China. The Kuomintang withdrew to Taiwan after losing control of mainland China to Mao and the Communists. I'm not super up to date on the latest claims between China and Taiwan, but Taiwan has never recognized officially that they do not rightfully control China.