Sometimes with these shows, trade and consumer, it is better for a company to wait and do a massive PR campaign - with global press events etc - separately for big launches like a 7D Mark II.
Reason being is that media at these shows are bombarded with releases and news from everyone and their dog at the shows, as well as all those aren't there but still hope to gain exposure during the days it takes place.
I am hoping Canon does announce something soonish about the 7D Mark II as I am really looking forward to learning the specs. As I am sure many of us are.