In the Operator Upgrade guide (https://strimzi.io/docs/latest/#proc-upgrading-the-co-str), we start with telling users to do a following command:
kubectl get all -l app=strimzi -o yaml > strimzi-backup.yaml

This command doesn't seem to work everywhere because of missing labels. It also doesn't backup everything and doesn't make it any easier to extract the changes. So I think this is virtually useless and just confusing users. I think we should replace it with generic statement about noting down any changes to configuration done after the previous installation since they will be overwritten. That might maybe make it more ambiguous, but less confusing.