When one can't wait for someone to fail and they'll be watching for it with delight.
Moreover, one may try to tip the scales, so that they "see you in the fall." It's a double
entendre that displays one's readiness for shadenfraude.
It's also a fine
sendoff after a paragraph of why someone messed-up, and the dolled consequences they'll receive. After which, one writes the phrase, making them wonder if it was being kind or rubbing it in.