Demotes after the banner

I'm actually hopping Nanna gets demoted. I'd like to build her up into a decent unit, similar to my current Serra. It'd also make her a lot easier to get with the optimal IVs. I can't really see them demoting any of the other units. That said, she'd be the first healer with two passives so there is honestly a chance she'll be a 5* exclusive ):

I wouldn't mind if they demoted some of the older 5* only units into a 4-5* pool, but I don't think we'd see that till the next update. What they have shown is they're listening to the feedback and trying to balance it. If they slowly adjust things with each update, that'll work fine. Or they might wait another 6 months then edit it again lol.

You're right that the 5* exclusives need to be available at 4*. Those that have been in the game since the start should now be available at 4*. This also doesn't cause the issue you've alluded to of good skills suddenly flooding the game as none of the originals have anything decent.

Probably Nanna. They wouldn’t demote Leif due to Personal Weapon and Personal B Slot

They obviously wouldn’t promote alternates.

Honestly, Nanna’s stats and weird kit scream 4* Healer. She’s like Maria on a horse.
I’d be perfectly fine if Nanna were to be demoted, I love her personality/character, and her art is AMAZING (MIWABE SAKURA DO NOT INTERACT)

I think it's either Nanna or nobody, they've done that before. The other ones have too exclusive skills.
I'm very satisfied with the recent demotion of 4*-5* to 3*-4*, so I don't mind if the summoning pools stay like that for now.