Enabling deletion protection on the instance is the correct strategy because it prevents the accidental deletion of the VM instance, thereby safeguarding your application from downtime caused by other teams' actions. While options like using a Shielded VM or a sole-tenant node offer security and isolation benefits, they do not specifically protect against accidental deletions. Preemptible VMs, being cost-effective and short-lived, are not suitable for ensuring uptime as they can be terminated by Compute Engine at any time. Therefore, the most effective measure is to enable deletion protection on your instance to prevent accidental disruptions.