The Classroom Explorer permits a growing number of bulk-actions that can assist in maintaining the best user experience in Google Classroom for teachers and students.
Because Classroom classes are not typically re-used from year to year, a maintenance action for teachers is to archive their old classes, which removes them from view in the student home screen in Classroom. When teachers do not archive old Classes, it can create clutter and confusion for students, so performing this in bulk can be a helpful administrative action. Archiving classes on behalf of a teacher is non-destructive and fully-reversible by the teacher.
Bulk-archiving can only be performed on classes that are currently in an "ACTIVE" state. Identifying old, unused classes within the Classroom Explorer can be accomplished in a matter of a few clicks. From the explorer, filter for ACTIVE classes that have a last updated date/time older than a specified cutoff. Select the classes of interest, click the three dots icon, then "Archive XX selected classes."
You will then be prompted to review and approve the archive action on all selected classes.
Modify the email to teachers to your liking, and then confirm the archive action. As noted in the default email text, teacher can "un-archive" their classes, returning them to an active state through the Classroom interface.
Additionally, teachers should be made aware that posts from archived classes can be "re-used" via the "Reuse post" feature in Classroom.