dance moms season 6

Nia has been bullying in the studio.Today Nia told maddie she was a total brat and it's not fare she gets all thr atttention.And in season 6 which they are now filming this new girl Karla joins the team ahes putting Maddie in her place and she is now abbys favourite!!!!!!!!!!!!!!!
and Mackenzie leaves ALDC big shock I know,even more suprizing Sarah from the select an samble team is replacing her.The reason Mavkenzie is leaving is in this true book and how do I know this????? I am in ALDC