You've arbitrarily decided Kaido "needs to die" just so you can say that Zoro will kill Kaido. There's nothing that suggests that Kaido "needs" to die, and there isn't much of a reason for him to die either.
if after taking down King we get to a scenario of Kaido vs All and Zoro manages to kill him I'm fine with that but Zoro helping vs Kaido from the start and then being the one who kills him hell no