I have asset listings where I have chosen only to show assets that are Live in the Asset statuses to list section. If a Website Author edits a Live asset referenced in the asset listing by changing the status to Safe Edit, then this asset disappears from the asset listing, until it has progressed through the workflow and becomes Live once again.
Does this mean that the only way to ensure that assets don't disappear off an asset listing when in workflow is to specify all the workflow statuses (such as Safe Edit, Safe Edit Approved, Approved, etc) in the Asset statuses to list section?
You could try selecting no asset statuses, that way Matrix will just check for permissions. If that doesn't work the way you expect then yes, you would need to choose all workflow statuses.