PublicFolder CN=Schema,CN=Microsoft Exchange System Objects,DC=contoso,DC=com

Since I ran into this one a couple of years later, and was frustrated to find no answers/followup, I decided to reply with my findings today.

The object of type 'Public Folder' is indeed an object stored in AD related to your Public Folder.s Check against your public folders (PS> Get-PublicFolder). If you are no longer utilizing Public Folders, it is safe to remove. For reference, Ali Tarjans article on Arbitration mailboxes does not list public folders in this location, from which you could also conclude this object is not required. https://www.alitajran.com/check-exchange-arbitration-mailboxes

My presumption is that it was automatically created by earlier versions of Exchange.