I've been a AA fan from the very beginning and is my favorite English related band. I have to say this new album they made was really interesting. Danny in a interview said basically that he wanted to do away with the old AA and explained why him and how him and the band wrote and why the wrote each song. That's why so many people are surprised on how different AA sounds now compared to back then and to be honest I agree with Danny 100%. There was a lot of drama that went down in the past and in the end this album in a way is a sign that the band moving on from the past they once had, to re-do AA over. The reason why you don't hear Danny scream a lot in the new album is because his vocals are shot from crazy drinking and previous AA events. They went on tour a lot, repeating songs and screaming from 2009-2015 did a number on his voice. So he needed to kinda work on his voice a bit with less screaming.
Thank god Denis is gone... JUEZUS
As for why he left/kicked out. He did a horrible thing which left the band in a bad spot in the eyes of all audiences. So he left and went solo for a time think it was country music he was doing idk :/ until he returned in late 2016.