Lying. Someone lied about something, then lied about something else and then made a big stink because it's a means to an end. The only time an ex-Liver would need to be approached would be to use their previous vocal work. There would be no residuals tied to the character designs or models. Those should be wholly the property of AnyColor.
Which I now have to ask the question: Are the Models maybe NOT the wholly owned property of AnyColor? Or was something doing "penny wise, pound foolish" about reputation laws?
Not sure about the Vtuber copyright law, but there is a specific cases we might able to refer: The incident of Gundam Sentinel
en.wikipedia.org
Important quote from this wiki:
"While Model Graphix would hold the rights to the story, characters, and mobile units, Bandai would have the sole copyright of releasing its models."
Edit: Here contained more info regarding this incident with some citations and sources:
www.zeonic-republic.net
It is a Gundam Novel where the main company Bandai designed and sell the Gundam plastic model kit, while the magazine company Model Graphix, wrote the side stories of this novel.
After the Novel was ended, Bandai had a fall-out with Model Graphix, so it resulted in complicate copyright issue (Bandai own the mecha design, but Model graphix own the story and character design). To avoid long-ass copyright lawsuit with Model Graphix in the future, Bandai only released the Sentinel Gundam plastic kit (or appeared in media/game), but without any pilot character (designed from Model Graphix) included in the merch.
So far this is the very strange case about copyright regarding the IP.
I think Kurosanji could actually try this route, where they could allow their talents to use or refer the "graduated" vtuber model (since Riku owned it) under specific condition (ahem* Last cup of Coffee *ahem), but forbidden to use the original roomate voices or AI-generated voices (to avoid the lawsuit).
However, I guess Riku is too lazy, or Kurosanji/KuroEN managements are a bunch of retarded people, hence resulting in Doki almost doing a backflip