When I say “Kubernetes-managed LB,” I’m talking about an LB created and managed on behalf of a Service of type LoadBalancer. When you create the Service, an LB is created automatically and all the necessary plumbing is done; when you delete the Service, the LB is destroyed automatically.
While it’s possible to do this yourself (create the LB, add the listener(s), add the targets, etc.) it is much easier (and more idiomatic) to let Kubernetes handle it as part of the Service lifecycle.
You can use Pulumi’s Kubernetes provider (along with the EKS provider) to automatically create the Service, although it’s entirely possible that the Helm chart already does that; I don’t have enough details about your Helm chart to know for certain.