https://www.youtube.com/watch?v=LLdoqxROjAQAfter she released her new mv, Inui Toko, Rindou Mikoto, and Hayase Sou reached out to congratulate her behind the scenes.
Marine asked Toko to sing it, and Toko told her that if she did Nijisanji would get angry.
To which, Marine told her that when she was making her mv, Cover "wasn't pleased", but she did it anyway.
So, 2 things:
1. If I'm understanding this correctly, it's pretty safe to say that most of the talents on both sides are unityfags. It's pretty much just the corps and fans that are at war.
2. Even though Cover didn't like the video, they still let her do it. That means either Marine has the power to just do whatever she wants or they're loosening up restrictions.