This seems to still be an issue. I am unable to get changelogs working when deploying tags because I can find no way to get commit of previous build.
It's most likely this line in the code: https://github.com/jenkinsci/git-plugin/blob/942de7ac00272c0bbad625a811a17e66713014b8/src/main/java/hudson/plugins/git/GitSCM.java#L1346