When clicking on the "Ship it" button for a release, the Ship Release modal appears with the list of unfinished features and provides you with the opportunity to specify which future release you wish to move them to.
However, if you click on the Release Status dropdown in the drawer page, the Ship Release modal screen does not appear.
For consistency sake, it would be desirable for either means of changing a release status to shipped to trigger the same process for moving unfinished features.
This would be so awesome!