In our example, our users have a polygon reference layer of well areas in ArcGIS Online. In Power BI, they have a non-spatial dataset which contains info about well locations. They would like to be able to join this non-spatial dataset to the reference dataset and then publish the results. This isn’t currently possible as to publish a Power BI report with a map to the web, any datasets coming from power BI must have XY data attached. (https://doc.arcgis.com/en/power-bi/design/publish-to-web.htm)
Currently, the users are working around this by adding XY data to their well locations dataset and simply making that layer completely transparent on the map. However, they feel the there would be a huge benefit to being able to join non-spatial datasets to spatial datasets and publish the results.