This is not about Google Drive revisions. It's about Google Docs. Clicking 'All changes saved' or similarly named link presents the document's version history.
It'd be nice to somehow include the versions (bonus points for who edited) in downloads. I don't really have an idea on how it'd be sane. Personally, with dedupe and snapshots being a thing, I wouldn't mind a copy of each.
That's all I have to say. It'd be cool, but I don't really see anybody developing it.