That UN vote is not about Taiwan being a part of PRC, it’s about who represents ‘China’ in the UN.
Exactly, and the Taiwan Province is a part of CHINA, which is represented by the government in Beijing (PRC), before UNGAR 2758 it was represented by the government in Taipei (ROC).
"Taiwan" is not a country, regardless of one's position on this they are either a province of the People's Republic of China or of the Republic of China.