The simple answer is yes and no, but the real answer is more complicated. There has been a lot written on this topic, and I am taking a shot at making this area more understandable.
Before getting started, it's important that I point out a key fact. k8s Upstream does not provide an Ingress. Like components such as service load balancers and storage, it simply provides the API that the controller should consume to create the functionality described in the k8s resource. An Ingress consists of the controller watching k8s APIs and the proxy engine that is programmed by that controller to affect forwarding.