I grew up in Michigan and that was certainly not the case when I was living in that part of the country. People knew and respected Oklahoma. (This was in the 70s.) The big boys back then were Oklahoma, Nebraska, Michigan, Ohio State, USC, Texas, and a few others. Ohio is pretty irrelevant in sports and the people in that part of the country know it. Oakland is actually in the Detroit area and I don't think I ever heard someone refer to it as OU.
I was mostly kidding with you anyway. I am sure there are some very misinformed individuals residing in Ohio, Oregon and perhaps a few other places that mistakenly believe OU refers to some school other than Oklahoma. Sometimes kidding doesn't go over so well on the internte.