It would be nice to believe, but when second place celebrates like she won says she wasn't aware of a rider up the road, it's not just not the story today. Perhaps if they had known and chased, Kiesenhofer still would have been able to hold them off, but we'll never know.
I also wouldn't call the rest of the peloton "unfortunate." They knew keeping track of the breakaway would be especially important given the lack of radio communication with a director in a team car, and they still didn't. I think Kiesenhofer deserves a ton of credit for this win; she was in the break from the very start of the race, and she was solo for over an hour, I believe. You can't do that without a lot of dedicated training and preparation. If anything, I think this is an example of "shoot your shot." You never know when things will break your way!
Part of the reason I love cycling races is that it's a combination of athletic ability and strategic thinking that you don't see in most other sports. The physics of drafting mean that a well coordinated group almost always has the speed advantage over a lone rider, but lone riders often win races because they don't have to deal with the coordination problems of a group. After 4+ hours of racing, people are trying to calculate optimal game theory decisions while at their max heart rate. It can be bonkers to watch!