Personally I think it would be fine to add it as an enhancement to WildFly. It is niche to need do it but it could be added. As you say, for a long time in standalone we have allowed connecting to the socket to trigger the scan. IIRC recovery-listener is disabled by default.
But a little bit against this logic there is defined a socket binding in the configuration (WildFly 17.0 Model Reference ). It is possible to communicate with the recovery manager through that socket to force the operation. Why that was not transferred to be an model operation?
Socket management is a big issue for many users so we expose the recovery socket to allow users to change the port.
I agree that we do not have a use case for adding a "trigger recovery operation": developers and tooling can use the socket to trigger recover scans and tooling can use internal mechanisms.