Task Manager user speficied Email Notification
As per the below document they are trying to say that Admin can enable user specific Email Notifications for the tasks, so that users can view the same from User Prefernce Screen for their Task Notifications. I could see the same feature is already in old release itself just trying to understand whats New in this Dec 24' Release in User specific to Email Nofiticiation
Within Task Manager > System Settings > Email Notifications, new functional groupings have been added listing all supported notification types. Service administrator can customize the default notification settings for all their users. They can allow their end users to personalize their notification settings using the User Specified option. If enabled, users can personalize their email notification settings within their user preferences (Tools > User Preferences > Notifications).