The commit message itself is way more eternal than GitHub ephemera. There's plenty of old codebases in git that were imported from SVN (or even older RCSes) wi

The commit message itself is way more eternal than GitHub ephemera. There's plenty of old codebases in git that were imported from SVN (or even older RCSes) with all commits intact. What's likely not intact is data in ancient issue trackers from decades past. git is a DVCS, so anyone can clone the repo and get all the commit information. Cloning the issues and such is not nearly so trivial, and isn't a part of the git protocol itself so there's no guarantee it's in any kind of interchangeable format. Important information should not just be in PR comments. It should be added into the commit information itself so that it'll be maximally available going forward. A good, fully explanatory commit message is a huge asset, and those commit messages will exist for the entire lifetime of the codebase. Anything else, not so much.