Knowledge Admin not getting notification when article is submitted for workflow

Summary

When the author submits an article to workflow, Knowledge manager or admin is not getting notification to add assignee in the workflow.

As we haven't given access to Author to add assignee, since we want only Managers can be added as assignee. If we add 'Manage Knowledge Tasks' privilege to authors, they can add themselves or their peers as approver and approve it, which is the concern of our client.

But if we do not add 'Manage Knowledge Tasks' privilege to authors, they cannot add approver. Someone who has admin access can assign, but there is no notification triggering to admin to notify him that there is a article submitted for approval.