As of now in Windchill 10.2 M020 :
It is possible to created document from template through Office Integration and Windchill UI.
But the same functionality is unable through the Windchill Desktop Integration.
However we can drag and drop the document for creating new Document or create a new Document but cant cant attach a primary content to it.But customers will be having Predefined templates on which they are supposed to work on .and It is important to enable this functionality in the user perspective.