Saya was also an ex-tsunderia, Kana
Lumi only became a manager down the line cause they didn't really have one and a lot of the bad shit got blamed on her. It's why there's that meme page floating around of all her "sins". It was 2+ years ago and Lumi has moved on from all that. She's also the most successful ex-cyberlive (Yuri you dumb bitch) and they do say success is the best revenge after all.
Coni apparently apologized to Lumi and Lumi forgave her. They may never collab but they seem to be on better terms than she is with the rest of ex-cyberlive. Coni shows up in youtube chat and twitter replies to a lot of the phase girls and will likely collab with Muyu at some point since they share a Mama and seem to get along pretty well.
They were all stupid girls in their early 20's and it's not really something worth holding against them.