When Kukuri senses the collapse of the Sunset Ravens' World Line and orders her army to retreat to their own World Line, she wishes them good luck and hopes they'll meet again. The Ravens' World Line ends up being pruned and revived as its own World Tree by the First Guardian, implying that the Ravens may never be able to visit Kukuri's World Line again even if Rein masters her new powers.
In the climax, Witch lets Kaname kill her because she saw a future where Shigeo would be alright, and she mentions that he hadn't become a Greed yet in the World Line of the past. Her Last Request is asking Kaname to not kill Shigeo. The World Line of the past is ultimately pruned, and judging from how Snow lost her human form when her D-Game Sigil was temporarily lost, Shigeo in the Ravens' World Line is implied to revert to a human being as his Greed subordinates/comrades blink out of existence.
According to the First Guardian, Kaname excised Shirogane from existence to stop the Greed from being created at all. The surviving World Line shows Shion never dying to a Greed forty years before Chapter 104 (considering the five-year timeskip, that would be thirty-five years before Chapter 1), implying that Kaname ultimately resorted to murder of a potentially dangerous man (whose Start of Darkness was Shion's death) despite his every effort to stop Darwin's Game without having to kill (under the assumption that Shirogane wasn't secretly Evil All Along).
