Wally recently left The Flash to pursue his own interests away from the influence of others. Still, Wally remains a hero who is always willing to help someone in need. When a threat to the multiverse comes, it would be rather surprising if Wally didn't run to meet it. The Flash's creative
team has struggled to give Wally a sense of identity and he often feels relegated to the sidelines so that Barry can save the day. Killing Wally would have an impact on fans of the character while removing the need for the writers to constantly attempt to explain the character's absence. It would also give the character one final chance to make an impact as a hero.