I do use Workflow Manager (WMX) and Data Reviewer a lot - but I've never auto-generated a report. While I haven't tested this recently, I'd be surprised if a new tool for exporting the report has been added (looks like it doesn't exist in 10.6.1, in the Data Reviewer toolset). While WMX can indeed be automated to various degrees, and while it can create Data Reviewer sessions and run batch jobs, I don't believe it has a built in way to generate the reports. Well, let me clarify - WMX does have a reporting function - so maybe it does to some degree; but it would not be an easy GP tool button-click "export report"; you'd have to do extensive formatting and some SQL work to get the results you need (to the best of my knowledge).
You do also have the ability to do those things mentioned - create a DR session, run DR batch jobs - outside of WMX, with the Data Reviewer GP tools. That could definitely be run by a ModelBuilder tool, or a python script. That toolbox does not have a tool for generating the report, though (in 10.6.1, that I can see).
If you have python skills, it probably would not be impossible to interrogate the Data Reviewer workspace itself, perform some joins and export the Data Reviewer results to an Excel sheet. One of my coworkers, I believe, has made tools that act on the Data Reviewer workspace and generate some derived outputs - exporting and reformatting the Data Reviewer results so that clients who don't have Data Reviewer could review the results. Unfortunately I don't believe we've created a tool to generate a report, though.