So for anyone not aware of why this is pretty interesting, both Coco and Rushia were two of the biggest talents within Hololive, a Japanese vtuber agency owned by the Cover Corporation. Both of them had subscriber counts going into a million and a half, and they earned a lot of money for their agency and themselves via superchats. Coco graduated (the term used in the vtuber industry to refer to retiring from either vtubing as a whole or just retiring a specific persona) at the start of July 2021 due to a combination of factors, such as unfortunately dealing with a lot of harassment from Chinese ultranationalists following an incident where the country of Taiwan was shown on stream (and the reason why said ultranationalists throw a shitfit over this is because the Chinese government considers Taiwan to be part of China itself, and "saying otherwise" will get you on the government's bad side), and also due to wanting less restrictions (her ability to collaborate with some other vtubers was hindered to differing extents from some parts of Hololive's management). Rushia meanwhile was actually fired from Hololive in February 2022 after she broke her non-disclosure agreement, having released some personal information about her true identity and employment with Hololive/Cover to a Japanese "drama channel" after accusations she might be dating another vtuber (it's generally acknowledged she had a poor lapse in judgment due to the stress caused by the "rabid simps" in her fandom).
Now one year after retiring from Hololive, Kson, the person behind Coco, has joined another notable vtuber agency, Vshojo, the first vtuber agency to be founded in North America. Not only that but it's also been pieced together by Rushia fans that the person behind Rushia is also joining Vshojo under the new alias "Amemiya Nazuna." This has caused some stir in the fandoms for both agencies, and while the majority of it is people being glad these notable talents have found a new agency they're happy with, there has been a vocal minority within the Hololive fandom reacting negatively. Namely accusations that joining a different agency is a "betrayal" to Hololive, or making up a conspiracy that Vshojo might be trying to "destroy" Hololive. Personally I find these ridiculous, but at least these people in the Hololive fandom are in the minority, and are eagerly awaiting Amemiya's debut in particular (Kson already streams regularly so for her not much has changed there).
I will say that, even as someone who absolutely disagrees with ANY notion that any vtuber agency are "rivals," it is still interesting to me how two of the top talents from one of the largest agencies have now migrated to a different one, and I do certainly hope the execs in Hololive aren't going to suddenly view Vshojo as some kind of "threat" and try and prevent any collaborations.