This is just a silly thought, but if next episode really is Nana/Meroron somehow (to contrast with the previous Nana episode being Uta/Nana), then I could see the actual Meroron episode being Uta/Meroron. I feel like they could unironically have every episode from the Uta superform episode to the Christmas episode provide fuel to a different ship, though I'm not committed to that theory until I see what they pull for episode 41 with Kokoro.