yeah, it honestly doesn't make sense from the current rules. If you follow the fold out rules from the decks or the Rule Manual from the website, you would think that, as with any "End of battle" abilities it would trigger even after a negate or an abandoned combat (if one of the combatants leaves play). But if you go to the Game Q&A under Revenge, you will see it doesn't.
The reasoning is the purpose of Revenge, it is supposed to act like Deathtouch from MTG, meaning you MUST resolve damage step for it to resolve. However they need to tweak the wording on the ability so it isn't contradictory.