>>65547001I see, so we are time-looping after all.
If so, then why those 3 left was already explained and laid out by them.
If we would like to discuss current events instead, then the writings were on the wall for a long time. The language barrier problem (on many levels) was something she mentioned herself during her last stream. But imo, another, even more important thing she didn't say, was that Mike was an unexpected success. It wasn't supposed to be like that, it was supposed to be just her alt. So all of a sudden she found herself in that strange position, where she would have to split her IP between two characters. Which I bet every manager on earth would advise against, especially for a small content creator like her - it's not like she's a company that can maintain several IPs at once.
I don't see any overarching connection between why Nyan/Vei/Silver and Nazuna left. They left for very different reasons, separated by a time which is considered long in such a young trend as vtubing.