The DATEX II Exchange Platform Specific Model (Exchange PSM) has not been updated since the release of the v2.0 documentation set. Therefore all references to the Exchange PSM in this v2.1 release documentation set refer to the Exchange PIM in the v2.0 documentation set which can be downloaded from here.
Updated WSDL for 2.1 can be downloaded here. Only change is that it refers to the 2.1 XML schema.