What? No, this vtuber thing is just very trendy in the anime community right now. The "her" is in quotes because the avatar is female, which is not related to whether or not they're trans.
Haha, this all is a weird reveal for me. In particular because now I know there are fewer people in Asahi Linux than I thought - since two of these personalities are one and the same.
Based on my own experience, you need to reevaluate your biases.
I’ve had many avatars online, some male, others female, many not human. While it can be for others, my decisions were never about my feelings towards my gender or sexuality.
I say this just to let you know these things are orthogonal. Just as you shouldn’t assume anything about a female child playing Peter Pan in the school production, you shouldn’t assume anything about a person’s gender or sexuality based on their “current” avatar (of possibly many current avatars).