Git needs a information preserving rebase

Indeed, the whole point of git rebases is that they are *not*
information-preserving. Rebase is a tool to discard irrelevant cruft:
typos, failed experiments, rejected patches, accidentally added binaries,
commits where you forgot to add "-s", and so forth.

If someone comes up with a way to import and archive patch review
discussions (perhaps in a separate branch or tree) and reference them
in git commits in a way that plays nicely with 'git push' and 'git gc',
then rebase should preserve _that_.