In "The Blind Assassin", Laura's death at the very beginning was, as we learn later, an escape from a restrictive and overbearing life. She was unhappy, controlled by Richard, and drifting in discontent. At the end of the story, we learn that Iris was the one who wrote the famous novel, but uses Laura's name, as a way to immortalize her; she achieves this, redeeming her sister's memory. Iris herself is looking forward to death and refuge, but only after she has revealed the entire truth.
In "Amsterdam", death is used as a form of revenge, but the characters enacting the revenge think that murdering the other one will bring salvation to their reputations. The cataclysmic double murder at the end was each character seeking refuge from the grievances the other had caused them. They thought if they could just get this person out of the way, then life would be better, and they could salvage the pieces.
It's an interesting question about two very well-written books, and I hope this helped!