There doesn't seem to be a Changelog file in Kibana record,
This forces us to monitor very closely the missing features requests and bug fixes to make sure we get them early on in a release.
Are there release notes somewhere?
No there's not, which sucks!
I've raised this GH issue to get them added moving forward.
We actually have provided release notes for major and minor releases of Kibana, starting with Kibana 4:
https://www.elastic.co/guide/en/kibana/4.0/whats-new.html
https://www.elastic.co/guide/en/kibana/4.1/whats-new.html