OP's reference to June 28 refers to the original offer found on the CIBC website that offers FYF after you spend $500. Jerry and Nabeel found other offers that gives FYF apparently without spending requirements.
Others can chime in with their interpretation but I think "This offer is only valid for applications received by CIBC on or before August 31, 2013" is pretty definitive to dispute the annual fee if need be.