At this point i expect nothing less from Niji, this is what happens when you prioritize short term gain by going for quantity over quality with your talents who are real people. They don't nurture their talent at all and instead are satisfied with signing as many people as possible and letting them do their own thing, hoping that one of the people they sign will be a rising tide that raises all ships. It has been successful for them so far of course, but stupid ass termination like this is what happen when you don't manage your talents probably. This business models has a very clear cap and rely too much on the vtuber themselves to do their own thing, it has made them money so far, but repeated drama like this, that will probably continued to happen, will just kill the company.
Now what I need Cover to do is just sign her for their next generation, Selen is friend with Mumei, like it is so easy just sign her