I think this overly-detailed, "convoluted" backstory is typical for most thoughtfully-designed themed attractions. The main difference here is that they're sharing it with the public like this so early in the process. Someone upthread shared the backstory document for Pandora, and it was similarly filled with details and in-world jargon while being short on narrative or emotional connections.
Based on other things we've seen, I don't think the document represents the storyline of the Tiana's Bayou Adventure. The ride seems like it will have a cute critters, a fun party story, and, well, some sort of adventure. The backstory might be better understood as a framework the actual stories of the ride, restaurants, and shops should fit into.
In the parks, they are retheming the mountain. They want to sell hot sauce and beignets, have a restaurant, a kitchen/cooking/baking shop (Eudora's), offer cooking classes, sell gardening/homesteading merch, brand all these things as being under the ownership of Tiana, and tie it into the Disney+ series and its characters.
This backstory document can serve to unify all these efforts in time/place/story. WDI teams are gathering props and sourcing materials and beginning to build out TBA, and this document can help provide context for things like blueprints, checklists, and plans.
It also seems clear to me that Disney is trying to nurture the fandom by sharing things like the "Beyond Thunder Mountain" blue sky presentation at last years' D23 and documents like this backstory. The goal of releasing this was probably to get us talking about the ride, to signal what's coming, and to appeal to those of us who like to be in on the process as it's happening. I could be wrong, but I don't think the document was designed to be a press release or a summery of the ride.