Prior to this update, when a document was created it gets a "document number". If the form configuration changes and a draft updates to use the new form, it updates the document ID. This will change it so that the form configuration changes do not update the number.

With this change, when a user creates a draft it will automatically be assigned a "document number". If form configuration changes are made and published before the document is submitted to workflow then the user who created the document will be able to update to the new form. 

The document number will stay the same when they update to the new form.

More info on publishing an App can be found HERE