OK, I misunderstood one thing. The question wasn't about Taiwan's response to Covid (which WHO had better be able to answer, politics or no politics), it was about Taiwan joining WHO. That
is a political question.
But:
> As for whether they're part of China - that's also a political thing.
Yes and no. No, they are not currently part of China. You have two separate governments, neither of which is subordinate to the other. Therefore neither one is part of the other. That's the de facto reality. It's not ambiguous, it's not subjective, and it's not open to interpretation.
But yes, it's political in that both sides claim a de jure unity - they just disagree about who's in charge of it. And it's political for everybody else, because they can't side with Taiwan without upsetting China, and they aren't willing to upset China.
But for China to try to pretend that the de facto situation is other than what it is... hey, we aren't blind, China. We know what the reality of the current situation is, no matter how much they try to pretend that it's something else.