I suspect that the message indicates successful joining to the cluster. I restarted the node and the logs are as follows:
[2019-09-09T10:00:12,284][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-deprecation]
[2019-09-09T10:00:12,284][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-graph]
[2019-09-09T10:00:12,284][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-ilm]
[2019-09-09T10:00:12,284][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-logstash]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-ml]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-monitoring]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-rollup]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-security]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-sql]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-upgrade]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded module [x-pack-watcher]
[2019-09-09T10:00:12,285][INFO ][o.e.p.PluginsService ] [elkcoord02.mycluster] loaded plugin [mapper-size]
[2019-09-09T10:00:16,843][INFO ][o.e.x.s.a.l.LdapUserSearchSessionFactory] [elkcoord02.mycluster] Realm [myrealm] is in user-search mode - base_dn=[my_dn], search filter=[(uid={0})]
[2019-09-09T10:00:17,164][INFO ][o.e.x.s.a.s.FileRolesStore] [elkcoord02.mycluster] parsed [10] roles from file [/etc/elasticsearch/roles.yml]
[2019-09-09T10:00:17,835][INFO ][o.e.x.m.p.l.CppLogMessageHandler] [elkcoord02.mycluster] [controller/120607] [Main.cc@109] controller (64 bit): Version 6.8.2 (Build f4a9b28c0d5114) Copyright (c) 2019 Elasticsearch BV
[2019-09-09T10:00:18,485][DEBUG][o.e.a.ActionModule ] [elkcoord02.mycluster] Using REST wrapper from plugin org.elasticsearch.xpack.security.Security
[2019-09-09T10:00:18,560][INFO ][o.e.d.DiscoveryModule ] [elkcoord02.mycluster] using discovery type [zen] and host providers [settings]
[2019-09-09T10:00:19,482][INFO ][o.e.n.Node ] [elkcoord02.mycluster] initialized
[2019-09-09T10:00:19,482][INFO ][o.e.n.Node ] [elkcoord02.mycluster] starting ...
[2019-09-09T10:00:19,654][INFO ][o.e.t.TransportService ] [elkcoord02.mycluster] publish_address {10.240.1.55:9401}, bound_addresses {[::]:9401}
[2019-09-09T10:00:19,667][INFO ][o.e.b.BootstrapChecks ] [elkcoord02.mycluster] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2019-09-09T10:00:23,591][INFO ][o.e.c.s.ClusterApplierService] [elkcoord02.mycluster] detected_master {elkmaster03.mycluster}{kpmhJBoYSQ6ocWgEPo-kTA}{_dNLkO_nTDKMrDxPdILnug}{elkmaster03.mycluster.mydomain.com}{10.241.4.119:9401}{ml.machine_memory=8182050816, ml.max_open_jobs=20, xpack.installed=true, ml.enabled=true}, added {{elkdatahot02.mycluster}{II5K2KjbQ_OXvJgBPo6sgw}{KQS6FVOuTQmP3DUSD0Blxw}[snipped] committed version [6727]])
[2019-09-09T10:00:24,695][INFO ][o.e.x.s.a.TokenService ] [elkcoord02.mycluster] refresh keys
[2019-09-09T10:00:25,179][INFO ][o.e.x.s.a.TokenService ] [elkcoord02.mycluster] refreshed keys
[2019-09-09T10:00:25,192][INFO ][o.e.l.LicenseService ] [elkcoord02.mycluster] license [value] mode [snipped] - valid
[2019-09-09T10:00:25,222][INFO ][o.e.h.n.Netty4HttpServerTransport] [elkcoord02.mycluster] publish_address {10.240.1.55:9411}, bound_addresses {[::]:9411}
[2019-09-09T10:00:25,223][INFO ][o.e.n.Node ] [elkcoord02.mycluster] started
[2019-09-09T10:00:50,131][INFO ][o.e.x.m.e.l.LocalExporter] [elkcoord02.mycluster] waiting for elected master node [{elkmaster03.mycluster}{kpmhJBoYSQ6ocWgEPo-kTA}{_dNLkO_nTDKMrDxPdILnug}{elkmaster03.mycluster.mydomain.com}{10.241.4.119:9401}{ml.machine_memory=8182050816, ml.max_open_jobs=20, xpack.installed=true, ml.enabled=true}] to setup local exporter [default_local] (does it have x-pack installed?)
The node is still not part of the cluster. Am I missing something? Let me know if I can provide any other info.