I think they worked out their latest album wasn't as good as it could be
They are actually touring soon playing Slaughter In The Vatican in full. It's a Nov through to Dec US tour with Extinction AD and Plague Years, would be a good show if Kyle can get the vocals sound right.
Slaughter in the Vatican was is one of thrash metal's classics. It was always going to be hard to follow that 20+ years later but yet they needed to do a bit more work on Mourn The Sky.
The King has had some great songs over his time and although not all of his albums work as a whole I love his ability to tell a story. He's a great concept album creator.