How is that a bad thing? They don't have computers in isekai land, they'll hate it there.
Well I specifically said "reincarnated", not "isekai'd". What if they get reincarnated into the same world, our world that is, in the modern era, and now they get to do a crypto rug pull as a young prodigy?
So is the First Rule of Vtuber Rebirths being unofficially discarded here or was it never really as big a thing as it is in the general fanbase?
If you mean mentioning past lives? No, not as big an issue anymore. Just don't use the old name on stream and you are fine. The VTubers want their old audience to find them. Just not the legal issues of using a name they could get sued for.