Has it though, really?

Google's company-defining products are (in my opinion):

  Search - not relevant to hiring practices, Search came before the company
  Gmail - initial version made by Paul Buchheit - 
    Case Western Reserve University in Cleveland, Ohio.
  Adsense - created by Oingo and acquired by Google
  Android - created by Danger and acquired by Google 
    (Andy Rubin - Utica College, Utica, New York)
  Chrome - basically Webkit, created by KHTML project and Apple

As far as I can tell, the breakthroughs Google has had are completely unrelated to any Ivy League hiring practices.