Understand the impact of deleting a NAT Gateway on outbound traffic and routing.
When you delete a NAT Gateway, the Reserved IP associated with it is released, and any private instances that rely on that gateway immediately lose outbound internet connectivity.
Because a NAT Gateway acts as the egress point for private subnets, removing it eliminates the route that translates private IP traffic to the internet. Existing outbound connections are terminated, and new connections cannot be established. Private instances remain reachable within the virtual private cloud (VPC), but they can no longer access external networks unless an alternative egress path is configured, such as assigning a Public IP or provisioning another NAT Gateway and updating routes.