I'm a repeat my reasons for saying no to them taking over the school again.
1) It might become repetitive, since that's how things were before. There's only so much murdering and oppression RP can handle before it becomes a cycle.
2) The good guys haven't had a chance to celebrate yet!
3) Bringing the DE back into power almost immediately would undermine the whole point of the battle, and make the deaths/injuries of students in battle worthless
4) I just think there's more unexplored potential with the good guys in charge
5) I also think precarious peace is more interesting than 'we're in charge, end of story.'