If she released a mini album though with 5 or 6 songs in, they would be all be upbeat but a album with 14-16 songs in would be a bit too much imo.

Besides, she's a Japanese singer after all. Not American. And Japan loves those ballads so they will always be there. Cute songs too. I don't think she will completely give up on those either, just write them in a more mature way like the way she wrote Milk Tea. :p
And I'm excited to hear that Winner Girls in that CM! :3
//When did my initiate change? Wow. Oh well, now I'm closer to (m)u era♥