Per https://www.ibm.com/docs/en/cloud-private/3.2.0?topic=console-namespace-is-stuck-in-terminating-state, you can delete the Namespace stuck in the Terminating Phase.
Recipe
1. Grab the namespace json
oc get namespace ma-operator -o json > tmp.json2. Edit tmp.json to remove the finalizer
3. Start the proxy
oc proxy &4. Delete the namespace
curl -k -H "Content-Type: application/json" -X PUT --data-binary @tmp.json http://127.0.0.1:8001/api/v1/namespaces/ma-operator/finalize