With Kelly, it would trigger an appointment and special election in 2026 per Arizona law.
It isn't without risk, but it's not a deal breaker of one thinks that another candidate can win there next cycle.
The safest picks would be Cooper, Walz or Beshear... Cooper and Beshear were both AGs when Kamala was AG from California, so they are going to be in the upper tier of people considered I would imagine