There is no path to Kubiak as the HC of the Saints. Either Kubiak does a great job which secures DA's job as HC or Kubiak fails and they both get fired.
If the Saints miss playoffs this year or don’t show clear improvement (not saying they will but it’s a what if) DA is 100% fired. They will not get rid of Kubiak after 1 season. So there definitely is a path. You can just say it’s not likely.