This makes no sense to me. The code is already self-documenting if written well, and all you need is a one line commit message to summarize that.
Doesn't the original conversation at least retain the context about why the change was made? A different LLM literally has no way to tell why you made this change besides guessing from the codebase and git history.
the mechanism is self documenting; context is not unless you pollute all your files with an ADR's worth of alternatives.
If a change makes sense, a different frontier model can usually figure out why it was made from the code alone. I take that as a signal that that the commit is good.
I believe they can do this due to having millions of public pull requests and github issues in their training data.