Tsunku said he noticed that lately, junior high school girls who want to become idols didn't belong to any sports club at school, which is something he didn't see with 1st gen MM. Pointing out a generational change.
Just speculating on what kind of auditionees he's screening right now to trigger such a tweet. I guess this means we should expect members the same age/younger than Maachan/Kuduu, and maybe not necessarily good dancers?