When publishing a document, an unpublished variant is not kept

When creating a new document, an unpublished variant is created and visible in for example a 'preview' facetselect. When it is published, it shows nicely in a 'live' facetselect, but an unpublished variant is not kept so in a preview mode is disappears.

Perhaps this is intended behaviour but not very handy from a site-developers point of view.