Elasticsearch added a "compatibility header" to handle this specific breaking change. We could simply add this header instead of adding an option.
https://www.elastic.co/guide/en/elasticsearch/reference/8.2/rest-api-compatibility.html

But they will remove the legacy code at some point. isn't?

Where would we set the $elasticsearchVersion parameter? Do we need adjustments to MonologBundle as well?

Where would we set the $elasticsearchVersion parameter? Do we need adjustments to MonologBundle as well?

it's not registred in the MonologBundle. I blogged in the past on how to register it: https://jolicode.com/blog/how-to-visualize-symfony-logs-in-dev-with-elasticsearch-and-kibana

Thank you @lyrixx.