Earlier quoted context omitted.
Something could have easily been lost in translation--on your end--there. For Taiwan in particular, there's a lot of nuance and purposeful ambiguity in its relationship with mainland China. The ROC's official policy is that Taiwan is just another province of China, which the ROC administers (along with part of Fujian province); the ROC, furthermore, is the legitimate government of all of China, including the island,…
> The ROC's official policy is that Taiwan is just another province of China, which the ROC administers (along with part of Fujian province); the ROC, furthermore, is the legitimate government of all of China To be fair, part of the reason that is the official policy is because the PRC is perceived to be (because it's pretty openly said this) more willing to be tolerant of dispute over which one governs all of China…
But the concrete disagreement mentioned in the comment I was responding to seemed to imply that the writer thought that his coworker might literally think that the ROC did not currently administer Taiwan, while she certainly does know that; it's a gap in understanding because the comment writer didn't realize that whether Taiwan a province of China is not how mainlanders conceptualize the dispute.
I would be curious to know if the average mainlander recognizes that most Taiwanese see themselves as having a separate identity and would ideally have a separate country, which is a real on-the-ground fact that I can imagine being glossed over in education and media.