I don't believe in such things as THE FINAL YAB tm but I do believe in death by a thousand cuts. One bad controversial event isn't going to kill Hololive but several of them stacked upon each other could. The end of the unarchived karaoke seems like the portent to such things. The incompetence and/or sabotage of their EN branch as well as lacking in getting more game permissions for their biggest vtuber that she'd rather not stream in protest over it is adding to it.

Now, in a hypothetical event that it does kill Hololive, would the established fanbase scurry to the other remaining vtuber companies still around? I think it not. An already niche subset of streaming will just get even more niche. It would be like if either of the big 3 in video gaming just left. Sure, you'll have some who stick around because they are gamers at heart who are there for the industry rather than one specific company but the rest will likely just leave because they know their favorite character or franchise isn't around anymore. A Hololive void would be more devastating than if Hololive was still around. Maybe this is just the boy who cried wolf and nothing will come of this and vtubing will continue on but in a different state. Nothing is recession proof and there is always a tipping point of how much people can take before they've had enough. I'd rather avoid the worst possible future if there is a way to prevent it from happening.