If you unpublish a virtual tour, the users won't be able to see them anymore. They will receive a message that the project is no longer published.
If you are using a different system to manage your website, you will have to remove or hide the tour yourself.
For developers, you can automatically remove the tour if he's no longer published by listening to the vent "amViewerProjectUnpublished".
You can also listen to the "amViewerProjectUnavailable" event to know if the tour is deleted or can't be viewed for other reasons.
Any technical questions about the integration of the tour can be directed towards firstname.lastname@example.org