Well, the ideal solution is that if there is more than one person on a task, they only see Done with My Part (see https://support.workfront.com/hc/en-us/community/posts/115001217287-Multiple-Users-Assigned-to-Singl...)
But if that is not possible, it would be great if the assignment status stayed Work or Request even though the task status is complete. That way, when someone accidentally completes the tasks and hits Oops I'm Not Actually Done, it will make it available for them as well as the others who weren't done. Currently it opens it back up for them but not the others. The PM has to delete them and re-add them to the task for them to see it in their My Work.