Is it possible to remove deprecated image stream tag?

Issue

• Deprecated images are available in the ImageStream.
• After removing image stream tags, either using 'oc delete istag' or editing the image stream YAML itself, an upgrade brings back the deprecated images.
• Example:
  PostgreSQL image stream is available with multiple tags in the OpenShift project.

# oc get is -n openshift
<snip>
postgresql  docker-registry.default.svc:5000/openshift/postgresql 10,9.2,9.4 + 3 more        13 days ago

• As per RedHat container catalog PostgreSQL 9.2 SQL database and some other versions are deprecated but still it is available in OpenShift image stream.