I'm actually shocked that they restored it for you and have to say tbh you don't deserve it being restored anyway. That staff was iconic for both a shadow priest and a holy/disc priest forever. If you didn't like the way it looked and the fact that it was so hard to get in the first place (but something tells me you didn't get it at 60) and then deleted it, you deserved to have it removed for you. That questline at 60 was horribly difficult (not as bad as the hunter one but still pretty damn bad). You are lucky you got a GM to restore it though.
somewhat related, Anethema is the main reason I'm so sad about the shadow weapon being a dagger rather than a staff, really gonna miss using it for my shadow spec.