Watching it it's definitely just Karen and Joanne who start it and then Daisy joins in. Maybe Ore as well, there's definitely a man's voice in there.
I have no animus with the Cliftons but that sort of thing doesn't come across well. It's all very well when you're shouting undermarked as a collective when Ed Balls gets mid 20s for a quickstep, but being more or less the only ones doing it, for a family member, for a dance that got a very high score, looks a little cliquey.