The final endgame cutscene shows that the Erdtree is still standing and sending out grace, meaning the Elden Ring and Marika is around in some capacity, so Ranni and her Lord can't have taken power. Plus, grace is the only reason tarnishe🐈d were able to be revived after death, and we don't have an alternative explanation for how revival works in this game, so I 🅷assume it's still the same, and for that to be so, we still need Marika around.