Can someone say how this differs from 'git rebase -i --exec' ?
It doesn't. It's just more convenient to use, and we took the opportunity to make people aware of the existing `--exec` feature.
It can be non-interactive now. Think "git rebase master"
git rebate... I wonder if there's also git refund, git coupon and git discount?
This makes it easier to not have broken commits (e.g. ones that don't build) in master, which in turn makes git bisect more useful.