An email notifications to the project owner for new requests added to a completed project should work even if a project is completed. This is crucial for anyone wanting to implement a change request process without going through the extra step of tagging someone in a comment since the goal of Workfront is to automate our workflow and getting people to tag someone in a comment as a final step is not a guarantee. It's also an extra step that should be avoidable if new request email notifications worked for completed projects.
We want to keep our change request project within the request queue of the project itself instead of a separate request queue in order to have a clear record of all change requests related to the project within the project itself. Email notifications are the only issue with our current process. I submitted this issue as a ticket and was unable to get it resolved.