Why does Toby disappear at the end of "A Rose for Emily"?

In addition, it is important to note that both Emily and Toby have only known the role assigned to them--she is the aristocratic and priviledged southern lady who is accustomed to servants.  He is the servant and has been groomed for that purpose.  Once Emily is dead, she no longer requires Toby's services.  Emily is freed from her bonds, and likewise, so is Toby.