The following article addresses how Classic Workflow Task Status Change Notifications currently function in Service Desk
Release : 17.1 and higher
Component : SERVICE DESK MANAGER
Found that the Activity Notification for "Update Status" applies on both Requests and Request workflows
Whenever a Workflow Status change takes place, an "Update Status" Activity takes place, which in turn will trigger the given Request to send out a notification if it is set to do so via the "Update Status" Activity Notification. This is the same functionality that is leveraged if one updates the Request Status directly.
Currently, there is no specific way to separate Update Status Notifications, ie: send Notifications only for Request status changes and not the Request Workflow status change.