Personally, I'd like to see this feature implemented as well. Since members with 1000+ posts are afforded the privilege of having a custom user title, I don't see the harm in those privileged users having the ability to change the title themselves as opposed to having one of the higher-level staff members do it for them.
As far as I know, turning on the ability would essentially just be changing a setting in the Admin panel (correct me if it's more complicated) and it would alleviate the queue (and inevitable topics like this, asking why the user title hasn't been changed). I can only see this as a win/win for the members and moderating staff.
But, you don't need to listen to me.