It’s time to move on.
Teachers can now delete any class/assignment. To delete a class/assignment, first, you’ve got to archive it! Once archived, you have to find the archived class/assignment by making them viewable in your folder settings:
Tap on the wrench
Turn on Show Archived
Go to your archived Class/Assignment - these will appear at the bottom of the list
Tap on Delete Class/Assignment
Deleting an assignment/class is permanent. You won’t be able to recover them.