ExtendedSocketOptions. SO_FLOW_SLA, SocketFlow and SocketFlow.Status were terminally deprecated in JDK 14 in preparation for the removal of the Solaris port. JEP 381 will remove the Solaris port in JDK 15 so the socket option and its supporting classes should be removed.
Note that jdk.net.NetworkPermission will need updated as part of the removal as it specifies the permissions for the SO_FLOW_SLA socket option. The removal will orphan NetworkPermission but it may be useful for future extensions in this the jdk.net module.