The more I think about it, the more impressed with the Sven and Olaf AAs (when they're working, that is). That being said, I think the human characters- Anna, Kristoff, and Elsa- look a little stiff?
I think the lack of story works here. You don't need a whole lot of story for Pirates or HM (... or Space Mountain). The Little Mermaid tried to cram so much in such little time, and it didn't work. Snow White's Scary Adventures works because it focuses on the Queen/Witch. Quick and easy to follow. Toad had an entirely new story.
If they did a condensed version of Frozen, it would literally just be the soundtrack with scenes (a la Little Mermaid), occasionally narrated by Olaf. The Hans twist wouldn't have fit the ride (unless they just showed it on a screen). By choosing a plot that only sort of highlights a couple things from the movie (Anna turns to ice and Elsa breaks the spell), it's relatively spoiler free. There are some people who still haven't seen Frozen, surprisingly. Actually, I know people who have never seen the Hunchback of Notre Dame, and that movie is 20 years old (My underrated favorite Disney film celebrated its birthday today), and it's part of the Disney Renaissance.
I loved Maelstrom, my family went on it on every trip, but it wasn't a ride that most people flocked to. It was a bit outdated (like everything else in Epcot), but it had it's charms. So I'll miss it. But I also miss the Viking boat playground that used to be in the front of Norway, and they took that out years ago. But Disney changes rides. And in some cases, that's okay. As much as I'll miss Maelstrom, and if they get the AAs working, I'll probably enjoy this.
What I'm really curious about is how the ride will perform tomorrow.