With the upgrade of the client libraries, the minimum compatible Elasticsearch minor version shits to 7.17.x.
When the server is lower than the expected version, the DXP won't start-up, but fail with an error in the DXP console:
10-22 10:45:22.619 ERROR [main][ElasticsearchSearchEngine:375] Elasticsearch node es-node-1 does not meet the minimum version requirement of 7.17