Problem/Motivation
The node preview system in Drupal 8 was written as a stop-gap solution with known deficiencies and hope that some day a more robust solution will eventually take its place.
Proposed resolution
Since the Workspace module provides a clean way to achieve "entity previews" in a non-live environment, we should be able to leverage it for nodes.
Remaining tasks
#2972622: Split the workspaces UI into a separate module
User interface changes
TBD.
API changes
Various node preview hacks will be removed.
Data model changes
TBD.