In 4.01 we added support for properties within a deleted entry. This allows us to omit the @odata.id, if key fields are included, and may provide other information about the deleted entry.

We are not clear, however, whether "properties" includes navigation properties and what the semantics of navigation properties on a deleted entry should be.

If you think of a delta payload as a graph of changes, the fact that a node within that graph has been deleted doesn't mean that you aren't interested in changes to other nodes within the graph; it's still interesting to report changes to nodes that may no longer be accessible (at least from the root) after applying changes.