Once a classroom has been deleted, at any point it can be recovered thereafter. Here is how to recover a deleted classroom.
1) Click on the "Classes" tab after logging into your account.
2) Once the Classes webpage pulls up, you will want to click on the "Deleted Classes" button on the left-hand side.
3) This will bring up a list of your deleted classes. To recover a deleted class, you need to click on the green "Recover" button to the far right of the classroom (it is listed under the "Manage" column).
4) Once the class is recovered, you can select it from the list of your classrooms on the left-hand side.
Please note that any students that are in a deleted classroom will default to the dropped status once the classroom is recovered and must be recovered themselves in order for them to show up in the classroom. For steps on how to recover a dropped student, please go to this page: How to Recover a Dropped Student