Full repro here: https://github.com/miparnisari/ionic-demo
When you run navigator.contacts.find() with the option 'desiredFields' set including 'displayName', this particular field returns as null for all contacts. However, if you do not set this option, the field is populated properly for each contact.
Also, it is unclear to me why when you use 'desiredFields' a full-blown object is returned for each contact with almost every field set as null. Wouldn't it make more sense to just return objects with those fields?