Holotranny has been the subject of doomposting since this thread was in 3-digits. I will point out that there's nothing stopping it per se. They, strictly speaking, have nothing against women playing male roles, men playing female roles, or anything like that. Neither do they stop people who have vaguely left-wing views (Kiara) or claim to be non-binary on twitter (Kronii).
The crux of the matter is that your garden-variety troon, especially the kind that causes trouble, is thoroughly unsuited for Hololive or any respectable job for that matter. Entertainment jobs require potential candidates to be reasonably sane, interesting to talk to, and not particularly annoying.
If there was a hypothetical troon who passed well, didn't push their bullshit constantly and was actually talented and interesting, I don't think they would mind. I note however that this is a tiny minority, and they have plenty of regular women to choose from.
TLDR, not impossible but not something to worry about
I hope they stay out of high-profile vtubing in general. Shuttling them off to Niji, where they will still get attention and collabs, is not a victory in any way.
I nearly forgot he existed. Apparently he's in Atelier Live now? He gets slightly more views than Pippa I guess (despite supposedly having 200k subs).