Data gets orphaned when grouped into a collection (2.8+) Has anyone come across a similar situation where creating a collection using ctrl-g (call it 'Collection 2') then removing that object's 'Collection 1' now results in that object needing to be restored from the Outliner's orphan data view?

Afaict, there is no documentation on how to restore orphan data, but I found out through trial and error that the only way to do so(and without needing to do a referring link to another .blend file which can access orphan data with 'fake user' still attached), would be to use two Outliner views, 'View layer' and 'Orphan data', then do a drag and drop from the latter to the other view.

https://developer.blender.org/T66086

I reported this as a difficult restore task to the blender bugreport as it is not documented on how to do this anywhere..

Adding a new collection with Ctrl-G does not send it to the scene (and is expected behaviour), but users even in this case should also be aware on how to actually "restore" this new collection that is now residing in the outliner's 'Orphan data' list. 

A user could be work with other collections, remove them, but leave just 1 collection still left intact, and so that last collection may not have been added to the scene, and that object just disappears without telling the user where...  Perhaps the developers can help improve in this area.

What do you guys think? Is this a bug or a supposed missing feature?

thanks for your feedback.
This is not classified as a bug, but rather a usability issue.
Anyone wanting more details can read the developer discussion here.
I hesitate to quote excerpts from that discussion in this answer, since the design will almost certainly evolve and change. But there seems to be some disagreement about how some of the functionality from previous versions of Blender should be carried over in 2.8 onward with regard to collections.
For now, users are better off using the M key when adding objects to a new collection.
More information about creating collections and adding objects to them can be found in the Blender Manual.