The Lucity extension does not automatically assume that a feature deleted from ArcMap should be deleted from Lucity. Therefore, if users delete a feature using the Delete key or some other method in ArcGIS Pro, the feature is deleted from the geodatabase, but remains in Lucity.
The Delete tools provides the following options
delete features from both the geodatabase and Lucity.
delete features from the geodatabase but leave an archived copy in Lucity.