I have two theories about that tweet.

First, it might be about Zen. Maybe Zen was being too clingy or got upset at Mouse for ignoring her, then seeing her play with Henya and Ari instead. Mouse might have finally stood up for herself, which led to Zen blocking her on Twitter and unfollowing her on Twitch. I’m not sure if it’s possible to find out exactly when Zen blocked her, but if the timing lines up with the tweet, that could really be what happened.

Second, it could be about VShojo. Maybe Mouse stood up for herself during some internal restructuring perhaps changes were being made to her contract or how the company operates, and she wasn’t okay with it. Geega also showed support who we know also left Vshojo like the next day, so if this theory is correct, Mouse might be preparing to leave VShojo soon.
Third theory: I am, in fact, Peepeehead in disguise, and I made all of this up.