As a tryout the services got stopped [1]
And nothing seems to complain about it.
We may be able to also drop the rocquencourt_legacy setup from kafka.yaml as well.
And decomission the zookeeper* nodes.
[1] https://grafana.softwareheritage.org/d/swL4gbeik/kafka-overview?orgId=1&from=1608052742652&to=1608054542652&var-cluster=All&var-instance=
Related to T2888