The Player->kill event is fine and will still be in v13.
The event being removed is Brick->killBrick, which destroys bricks as if they've been hit by a wand. Because this can be abused with the wand trust system (you aren't allowed to wand bricks you don't own, yet you can place events on them with full trust so onActivate->Self->killBrick can happen to destroy peoples' builds anyway) it is being taken out.