Incorrect. The performance advantage of deeper wheels increases with yaw angle. It's the apparent wind angle that counts. Riding 25mph with a 10mph crosswind yields a yaw angle of around 22 degrees. Yaw angle decreases with rider speed. The only time you're likely to see a 90 degree crosswind is if you aren't moving. In the graph below the red line is from a set of Mavic Open Pros: