Potsdam Declaration 

Here some quotation from the "Official Gazette of the control council for Germany" (Documents relating to the establishment of the Allied Control Authority) - published by the "Allied Secretariat" in Berlin, Elssholzstrase 32.

Under item VI (Statement by the Governments of the United Kingdom, the United States of America and the Union of Soviet Socialist Republic and the Provisional Government of the French Republic on the zones of occupation in Germany) they write:

"1. Germany, within her frontiers as they were on 31st December, 1937, will, for purposes of occupation, be divided into four zones, one to be alloted to each Power as follows ..."

Under item  VIII (Report on the Tripartite Conference of Berlin) and there Article IX concerning the western frontier of Poland they write:

"The three Heads of Government reaffirm their opinion that the final delimitation of the western frontier of Poland should await the peace settlement."

Until this peace conference the disputed territories "shall be under the administration of the Polish State and for such purposes should not be considered as part of the Soviet Zone of occupation in Germany."

So keeping in mind this facts sincerely it´s obvious that the (West-) Allies didn´t order any transfer of Germans out of their ancestral homelands because by doing this they would have created a fait accompli. 

Actually Russia and Poland created such accomplished facts by expelling most of that Germans - even quite long before the Potsdam Declaration. 

(Comment: Any forced transfer of population is a crime against humanity; and this it was already at times of 1945 - Nazi-Germany was trialed exactly for such crimes, too.)