Yes, if they only change 2-3 songs a night that will add up to 35 more songs, which will take the full total into the 80 range but still be not what we were expecting!

What about the full album play throughs they promised?

They surely can't play 12 lots of that core set they played last night and expect people to be excited?
Out of the 12 shows I would expect 4 to be full album play throughs, 1 in every 3 shows should be wildly different. Maybe even an accoustic show somewhere - although with the lights, screens and robots all programmed upfront I'm starting to think there will be less flexibility that we were imagining.