Trusting the messages to contain specific keywords seems optimistic. I don't think I used "emergency" or "hotfix" ever. "Revert" is some times automatically created by some tools (E.g. un-merging a PR).
For the stuff I've worked on, if you want to know about bugfixes and emergency releases, you'd go to Jira where those values are formalized as fields. Someone else in the comments here had a suggestion which just looks for the word "fix" which would definitely capture some bugfix releases, but is more likely to catch fixes that were done during development of a feature.
Yes for a meaningful context you should need both the source repo and the work tracking system. But today most systems have apis (jira, ADO, gh, ...) so this should be fairly doable, especially using a bot like copilot cli. But it's not doable as a little shell script.
