Having had family members murdered in Auschwitz and having visited the camp primarily to say kaddish for them, I do not believe that restoring it to how it was will serve any positive purpose. In its present state it serves as a very clear witness to what happened and also as a fitting memorial to all those who were slaughtered within its confines. Why anyone would want to rebuild such a monstrosity is beyond my understanding. It seems almost ghoulish to want to do so, even dishonouring those who died there by disturbing their graveyard. There is already a mass of documentary evidence, sufficient for anyone's needs who want to know the minutiae of what happened there. Those who don't will not visit anyway.
Islamic State destroys part of Syria's Temple of Bel, monitoring group says (Reuters)
from the article: A German-Israeli team undertakes the reconstruction of Auschwitz