We used to use Query Layers to append into existing ArcSDE Feature Classes but something changed in recent releases and the ability to do this. The problem is Arcpy cannot determine the difference between Multi-point vs point feature class in the query layer. This requires us to save a LYR file with these properties to be set for arcpy operations to be successful.
Please allow ArcCatalog, ArcMap, ArcPro the ability to auto-detect the spatial data type. Multi-Point, Point, Polygon, Multi-Polygon should able to be determined based on the spatial engine.
Spatial databases provide the type to be determined based on a spatial property so assuming the Query layer supports all of the ArcGIS rules, why can't it determine the spatial data type?