I'll interject briefly here. I've seen no one raise the obvious objection towards building a new Moana flume ride in Adventureland.
Flume rides mean that younger guests might be unable to go on the attraction. I assume that this Moana attraction is aimed at appealing to young children who enjoy the Moana film on Disney+. If so, a flume ride with a height requirement similar to Splash Mountain Tiana's Bayou Adventure (40 Inches) would disqualify many guests that this attraction would appeal to. I double checked the CDC guidance on what to expect for height measurements of children. It looks like most 4 year old girls would be unable to ride an attraction with a 40 Inch height limit. Even a portion of 5 year old girls would be losing out on the chance to see Moana. We could foresee a ride with a less-intense drop that could result in a lower height limit. But you'd still be cutting out 3 year old girls. And even if the ride can be safely ridden by these guests, there's no guarantee it would be enjoyable for the important 4-5 year old demographic.
If a Moana ride gets built, I expect it will be accessible to as many guests as possible. Disney's incentive is to provide an attraction similar to what they've just built at Fantasy Springs at Tokyo Disney Sea. Those rides are impressive, but they are not physically taxing. They prioritize audio animatronics, special effects, and music.
I could be totally misreading this, but I think they would be making a mistake to build a thrill ride when families really want something that is accessible to everyone. Just my two cents on the matter.