The more I think of the plot for the attraction, the more confused I get. Looking in a bayou for musicians doesn't make sense to me as a story for a Princess and the Frog ride. I thought Louis was a unique circumstance, so wouldn't it be easier to find a human band? Maybe I missed the backstory and Tiana planned the party too late, so all the human musicians were booked at other Mardi Gras parties already.
I also started to think of what it'd be like if this is what they used as a plot for something like the Little Mermaid. For most of the ride the only characters are Ariel, Sebastian and random sea creatures. Let's find some ocean animals to play in Sebastian's concert. There is no Ursula anywhere. Maybe you see King Triton using some magic to make you smaller for some ridiculous reason and you pick up some musical shrimp, then voila, you are ready to get big again for the concert and finally get to see the rest of the characters in the finale. I find the idea lame.
I don't understand why they didn't use the plot of the movie. If they were doing a classic ride from scratch for Tiana, it wouldn't be nearly 10 minutes. It'd probably be closer to 3 or 4. The frog thing wouldn't be that big of a problem because they could still include at least 3 human animatronics of Tiana in different dresses: an "Almost There" scene, Charlotte's party where she meets Naveen, and a big finale in her classic green princess dress. They could also have a Dr. Facilier scene and a scene where Tiana and Naveen are frogs falling in love in the bayou. It's all from the movie and would've made a wonderful dark ride for families. We don't have enough of those.
I still think that this was the wrong property for Splash's bones, it shows with how contrived the story is, but they can't undo that decision. They should be thinking of a plan B now though to improve what was delivered.