I believe it is by design. The reason I say that, is when you restore a project schedule, it puts it into the draft database and not the publish. So to really get it back, it then needs to be publish and go thru all workflow stages to get it back to
where it was. The backup and restore is just for the schedule and does not bring back all the workspace and workflow settings.
Cheers!
Michael Wharton, MBA, PMP, MCT, MCSD, MCSE+I, MCDBA, MCC 2011
www.WhartonComputer.com