It may be difficult to organize a century ride, always in optimal riding conditions. But it is something that can be considered.
In this case, the sun would have already been getting better by mid-morning when the accident happened, although perhaps shifting more from east to south.
I probably wouldn't have worried about the sun by 9:00 AM, although I was driving up in Washington a few days ago, and found myself shifting the visor around at about 10:30.
While recreational riders can choose their routes, commuters have other demands on the times and routes they take. And, aren't blessed with safety vehicles.