alt Hacker News> reunite
This is the incorrect word to use since the PRC has never held territory here. If the PLA sets foot on Taiwan, that's an imperialist invasion, nothing less, unless the people of Taiwan have democratically chosen to abdicate their government for CPC rule, in which case the word should be "unify" or "merge."
Reunite is not incorrect in the broader sense.
We use the term "reunification" for Germany but the Federal Republic never "held territory" in the Democratic Republic. However, of course both states were the result of a split of "Germany". This is the same with the ROC and PRC so bringing both sides together, whatever the mean, is a reunification in that sense.
The narrative of rejecting the term can be said to be broadly propaganda but plays on a peculiarity that both sides don't recognise each others.