The 0.13.x major release of Great Expectations deprecated Validation Operators and added new features such as "new style" Datasources, modular Expectations, and an improved Checkpoints feature (introduced as part of the 0.13.7 release). These updates led to the deprecation of much of the API surface utilized prior to the GX 0.13.x major release. While we maintained that API surface through two major revisions in accordance with our deprecation policy, it has been fully deprecated as of the 0.16.x major release.
Since the deprecated features and API surface are no longer present in the current GX code base, we will no longer be maintaining the migration guide from pre-GX 0.13.x processes to post GX 0.13.x processes in our current documentation. To see the document as of the last version to of GX to support the pre-GX 0.13.x processes and API surface, reference the GX 0.15.50 documentation's migration guide.