This question was asked by a customer in a recent JUMP session:
Understanding and Configuring ElasticSearch for IBM Connections (on prem)
IBM Dev provided the following answer sometime later:
"Technically speaking, yes. You would need to install the new K8S or Docker based ES cluster then migrate (remote re-index) the data from old standalone ES cluster (after disable client certificate based authentication).
As we have not tested or documented how to do this yet however, we unfortunately would not be able to Support such a procedure."
This Enhancement Request is a request therefore for IBM to officially support such a migration path (from standalone ES to Component Pack ES) in the future.