I can't speculate about fans who were not forum members, but I suspect most had no idea. But on the forums, there had been speculation posted that they might do that given (1) that it was announced that it would be a special show, and (2) Octavarium really lent itself to having an orchestra. To add to that, they had been regularly rotating 4 of the 8 movements of Six Degrees on the tour. In the last few dates leading up to that show, they rehearsed the other 4 movements in sound checks (I think they actually played the two in their sets). I remember sending a PM to hef saying: "They are going to play all of Six Degrees! Probably with an orchestra!" Or something along those lines. But, again, outside of the forums, for the general public who doesn't follow every set played and every announcement from the band, I don't think many people deduced what was going to happen.