Damn, I was totally blindsided by this just now.
Used to be a huge fan right from their first EP Half Hour of Power up to the album Screaming Bloody Murder. Don't listen to that much newer stuff from them but always try to catch one of their shows when I can. Saw them in Calgary a number of years ago.
I guess they announced this today as a way to get ahead of the media but they are going their separate ways after they finish this upcoming tour, new album and finishing off their career with a worldwide farewell tour. So still plenty of time left. Doubt we'll see any reunion tour either as these guys all have their own thing going on and the buck stops of Whibley.
https://globalnews.ca/news/9681982/sum-41-breaks-up/