As we now install both knativeservings.serving.knative.dev and knativeservings.operator.knative.dev ,

installing KnativeServing with

apiVersion: operator.knative.dev/v1alpha1
kind: KnativeServing
metadata:
  name: knative-serving
  namespace: knative-serving

using

oc get knativeserving

works only on some installs (seems random, probably depends on which of the CRDs gets created first)