Like everyone else, she's an idiot. Giving them a proper high school experience won't solve their issues.
But with Otonashi's help, they might be able to do it together.
The first step is to reestablish the status quo. Without an enemy to fight, Battlefront is directionless.
Tachibana turns them in for manipulating her exams. They chalk this up to her losing against her angry selves.
But she's really acting under Otonashi's direction, to arrange a resolution for people.
But can he even do anything for Yuri?