Oh yeah, that was the whole point since first announcement.
Obviously they can't play all of them. Especially at the shows on weekday evenings
I agree rotating the albums is the most likely thing. I was expecting the second headliner to be Testament (who suspiciously cancelled their one confirmed date on the Sweden Rock Cruise, so I have a feeling they were going to be the headliner), so am very disappointed with Sepultura.
And since Exodus played this tour last year, I really can't be bothered to travel just for Heathen and Destruction, who both already toured Europe this year on Overkill's Killfest.