In Poland, those who were considered Aryan by anthropomorphic standards were assumed to be of Germanic descent and thus non fully Slavic. Some of these 'racially valuable' kids were sent to Germany to be raised in German families.
I'm not sure about the ahnenpass but acc to Wikipedia;
'The Nazi ideology limited the category Aryan to certain subgroups, while excluding Slavs as non-Aryan' so I believe eg. Ukrainians with ahnenpass were believed to not be fully Slavic and of Germanic heritage as well.
Hitler feared Slavic influence in Austria, which he expressed in 'mein Kampf, and his opinion of us was rather negative. Obviously, it is not only him who set the rules, but he was certainly the pioneer in creating the 3rd Reich.
Another thing is the case of P[UWSL]oles in Nazi Germany working on a construction, or doing some simple labors; they could not have sex with local women or vice-versa, the punishment for it was death. [/UWSL]