Quick summary: The last_archived base field was added to asset entities in farmOS 4.x and was immediately deprecated.
Details:
The archived base field on asset entities was changed from a timestamp type to a boolean type in farmOS 4.x, in order to repurpose it for storing the archived state of assets, which in turn enabled removing the status field.
For more context see: https://farmos.discourse.group/t/proposal-remove-status-field-from-asset...
The last_archived base field was added at the same time, in order to preserve the timestamp data that was stored in archived previously, to give users a chance to decide if they need it or not.
The last_archived field will be removed in farmOS 5.0.0. If you need this information then you are encouraged to migrate it to another place.
The Asset::getArchivedTimestamp() and Asset::setArchivedTimestamp() methods will be removed at the same time.
