Currently, Issue in Epic panel will appear only when the user have Jira Software license. When a non-software user only need to see stories related to Epic, they would need to have a full Jira Software license which will provide them access to board, reports and Sprint which they does not need.

Suggestion

Make issue in Epic feature global so that all the users including non-software user to be able to view the stories related to Epic without the need to create duplicate issue link.