(Author here) Yes, "release notes" is probably the appropriate term. The issue remains however: many projects generate their release notes from their git commit messages.

Regarding the conflicts issue, this is where tools like Changie can help: instead of modifying one single file, every merge adds its own separated entry. They are then assembled together at release time with `changie batch $VERSION` to produce a single file for $VERSION, then merged into the global changelog/release notes file with `changie merge`.