There is the idea that new members tend to push the older ones to need to stand out more/improve more to compete with the new girls. It's a much needed inner rivalry which could be exactly what they need (some of the girls, like Riko, seem to be coasting rather than actually pushing themselves).
I just think it's funny it actually happened while we were discussing it

. Mao going up herald Tsubaki becoming more dance focused. They have potential to be very clean dancers (like C-ute) so I kinda hope they do.
Saori is so adorable, I'm super okay with her being put in Tsubaki. I much agree with what Amped said in the Tsubaki thread, she's got an ace/front girl quality to her that would benefit Tsubaki right now.