My sister was a competitive gymnast all growing up and was very good, on an olympic track. She suffered several injuries and, heartbroken, had to stop the sport. She looks forward to seeing the gymnastics in the olympics so much... and my uncle told her during the 1992 olympics who won the gymnastics final, before she had a chance to watch it on tv. he had looked the information up online. She has never forgiven him for spoiling it for her. She had waited 4 years.
I think this story relates to your Harry question. There is nothing worse than a spoiler. Some people are busier than others and it is no one's right to spoil something that would and could be enjoyable to someone else, just because they beat them to the ending. I have a few pages left, and I'm very happy that I've managed to not let any of these people spoil Harry for me.