When adding text to the refrenceData field for a property when you goto Export Cypher, you'll see that the property Data Type is no longer there, just the reference data.
Example Export Cypher before and after adding referenceData:
MERGE (4 :Activity {activityId:'String'})
but then add text to reference data field...
MERGE (4 :Activity {activityId:'this is my referenceData text'})
It would be nice to have both the dataType and the referenceData text both available on the exported model. We are using referenceData to provide what the properties mean in the context of the business and data model.