In App Workspaces you should be able to select whatever Dash/Rep/Dataset you wish to Publish to you consumers of the App Workspace BUT if you select (for example) only the Dashboard then it really must send along just the Dashboard visible but all Related Objects (reports/datasets) in the "Package" be published as well -
but as HIDDEN objects (like you can with Datasets now).
This way the Consumer would only see the Dashboard and all its tagged Reports visible but NOT the actual Reports as separate items to view (they must be there but not visible.
This is REALLY important if you create a PBID file with a Dataset (i.e. a PB Service Dataset) and you create multiple Charts and Matrixes out of THAT data in a single OBIX file BUT you only pick certain ones for the particular Dashboard of a particular App Workspace. Therefore Reports pages NOT marked to be "INCLUDED IN APP" but that have been "Pinned To A Live Page" will NOT be visible to the consumer of the App Workspace but will be there to feed the Dashboard that is visible.
Right now if you do NOT include the Reports from which each part of the Dashboard is sourced then the Dashboard comes up blank.
This is confusing to users who just want the Dashboard.
AND where this would be REALLY useful is if you subsequently Publish the PBID file to a different App Workspace (which has the same Dataset exact Datset in it) but to be used for a different audience than the first one (say the first one is for line operations and the second one is used for senior management but still needs SOME reports the same as the first App Workspace).
This way you can bring consistency to your reports by having one PBIX file with Pages based on a single Dataset and you can expose all these Charts and Matrixes in both App Workspaces from a single resaved PBIX file thus necessitating only one version of each Chart/Matrix and allowing the App Workspace to include only the objects in the Dashboard that are relevant to its audience (and no more).
This is VERY important to me asap (of course) :-)