I generally don't follow this kind of stuff too much, but read up a little on it now.Beats me, I don't watch the show and I have very little context here. I just find the entire thing weird and dumb. Kagami actually watches the show and follows stuff though, so he's in a better position to speculate about that.
A couple days ago Kikuchi from the music group eufonius (Kokoro Connect OP singers) made a flippant remark toward Halko Momoi that pissed people off.
Then unrelated to that, there was an odd occurrence in which the head of Silverlink, Kaneko Hayato, tweeted that Ichiki Mitsuhiro (the pranked VA) would be in Kokoro Connect after all, starting with episode 14, and that that had been planned from the beginning...but the tweet was promptly deleted for some reason. Maybe they'd wanted to keep it a secret.
That seemed to have started people who weren't aware of the original pre-air event searching to find out what this deal with Ichiki was, and it turned out to be ammo to pile on the Kokoro Connect hatetrain that was just starting to roll with eufonius.