I'm just dropping in on this thread, and let me start with something I said over on reddit:
Yeah, this didn't even have to be an event banner, either. We could have gotten an Archanea or Valentia banner since it's been a while since we've gotten either. Or give us the Binding Blade banner right now, instead of waiting until March! Nah, at the rate we're going, we're gonna have more Camilla alts than there are episodes of Sesame Street.
And if they really wanted to make an event banner, let alone a banner like this, they should have just added characters that haven't gotten alts yet, or even better, characters that don't have their regular variations available yet. I don't know anyone else in this thread has said this, but they missed an opportunity to add Izana. IS could have just added his regular variation and make him the Tempest Trial reward because of the fact he joins you if you upgrade your hot springs to level three. As for adding other new (Fates) units, they could have added Orochi instead of Elise. But like I just said, this shouldn't have even been a banner. They should have just gave us the BB banner here and now, or give us a new Archanea or Valentia banner.