Metallica mistreated Jason Newsted, the replacement of Cliff Burton, for 14 years, as a way to cope with grief. He exit the band and Metallica almost disappeared.
In Slipknot case, Paul Gray's death, one of the key members of the band, started a progressive replacement of various members, including Joey Jordison. All of those firings were quite shady, and nowadays even the band itself acknowledge that they're not close as they used to be.