Except that AC/DC, despite all their grief, kept on producing after Scott's family assured them he would have wanted the band to keep making music.
It's not like Slipknot has much of an consistent schedule, from being 2 years (Slipknot - Iowa) to 3 years (Iowa - Vol. 3 [The Subliminal Verses] to 4 years (Volume 3 - All Hope is Gone) and to 6 years (All Hope is Gone - Vol. 5 [The Gray Chapter]).