Towa taking a one-week break
I don't think it's necessarily on Cover that this is happening the way it is. Or at least, Cover aren't handling their business any differently than any other Japanese company would.
We know for a fact that, in regards to management getting in the way and blocking creative decisions/ideas, Marine, Pekora, Haachama (who I believe also sees the writing on the wall given the timing of her indefinite hiatus), and practically all of Holostars have voiced their disgruntlement. Pekora had to private a stream where she broke down crying that one of her ideas was knocked back. Astel made a video apologising to his fans that he felt he wasn't good enough for them because he couldn't do all these things he wanted to and got stuck in an APEX rut as a result. Haachama was in and out of hiatus whenever policy changes wiped her videos for unknown periods of time.
We also know that Shion's roommate had suicidal thoughts, Calli's mental health is in flux, Korone and Aki have both thought about retiring already. This is a 'dream job' with crushing amounts of pressure.
On July 1, I think all of them realised that no king rules forever. Kiryu fucking Coco of all people - a woman who on the backend was experiencing these same restrictions and pressure as others - decided that she wanted to go and do her own thing, and I think this has opened the door for others to start contemplating the notion of leaving.
This isn't really a 'Cover bad' thing. If you consider yourself a Creative and you work in a creative field, having that creativity diluted and restricted is the single most morale-crushing thing you can deal with. This happens in every industry in every country. Movie productions have internal disputes, people leave bands because they no longer want to create that type of music and feel suffocated etc. It's just how it is.