While there is overlap between vtuber communities and HN, the culture is quite different. When one does come up, it is eternally September on HN. In vtuber communities/culture, the persona of the vtuber is treated as entirely separate from the person behind it, even in cases where it's exceedingly obvious (e.g. someone leaves an agency to work independently).
At the very least, it is rude to disseminate, draw attention to, or even speculate aloud about the identity of the person behind the avatar. Typically it's considered harassment/doxxing (I believe this is because vtubing culture is largely derived from Japanese idol culture, which appears to be structured around dealing with stalkers). That is to say, "upholding the kayfabe" is a bare-minimum of respect.
I could see why people on the Asahi team considered HN to be a host of harassment, considering even a cursory search of HN turns up comments "compiling evidence" about Asahi Lina's identity (including one still-up comment that straight-up links to Kiwi Farms, which is almost certainly done for purpose of harassment). I'm not sure if Hacker News ought to be moderating comments that deconstructs pseudonyms where clear effort has been made to separate it from the person behind them, but I also empathize with not wanting to be linked to accordingly.