Move Request Craziness

I am in the middle of migrating our Exchange 2010 environment to Exchange 2013 CU9.  I want to remove theGeneral Mailbox from the volume it currently resides on and onto a new volume with more space (the volume with more space houses a database that we no longer need and will be removed).

I created a new volume and database called TempDB and then moved everything from theGeneral Mailbox database to the TempDB database.  When I runGet-MailboxDatabase -Identity "General Mailbox" | Get-Mailbox, it just returns to a command prompt signifying that no mailboxes reside on that database.

When I run Get-MailboxDatabase -Identity "General Mailbox" | Get-MailboxStatistics, it lists all of the mailboxes that were previously on the database.  I am not quite sure why it doesn't just return to a command prompt since there are no mailboxes that reside on that database.

The other reservation I have about removing General Mailbox is that the database is still showing that it is using roughly 10GB of space.  That space is being used by theWSECU General.edb file, so I am very reluctant to remove it.  I would assume that after moving everything from General Mailbox > TempDB that the database would show as being empty.  Is this not the case?  Am I just being paranoid?  Is safe to delete the General Mailbox database?