You don't have to worry about spoilers if you have self control. I do not have self control.
I do have self control. I'm actually paranoid about it
when Iron Maiden started touring last year I stopped checking ANY of their videos on YouTube (to avoid suggestions, that are always recent), disabled notifications on FB groups about them, and stayed away from the topic about it on this forum.
This time around it will be a lot easier, just a few days of the tour and I'll already be seeing them in Milan so I'll just have to avoid this thread and the Concerts section for a week.
I can only speak for myself, but setlist spoilers are nowhere near movie spoilers. In fact, to me setlist spoilers aren't spoilers at all. It's like being handed the evening program when you walk into a classical concert.
I disagree speaking for myself as well, while I understand the comparison, to me a concert it's not a Winamp playlist performed by the actual musicians. It's a show, a performance, a presentation, it's the whole excitement and adrenaline rush of enjoying live music. I can forget about time (hard to forget that only 7 songs are missing when you know the setlist), I can hope for my favorite song to be played, I can listen in anticipation to the funny or witty introduction the singer is doing trying to figure out which song it is, and so on.
This especially in metal, and more specific with Dream Theater that have an "anything goes" attitude to setlists, so potentially any song could be played. It's not a boyband concert where everyone just want to hear the hits, and the hits is what they get.