Of course we get a background, "Dumbledore is gay" reveal. Bet they intend Raya to be Bi/Pan too, so all shippers are valid. Some people go into children's stories these days like they're playing a Bioware game. All they care about is romance options. And this reeks of She-Ra, Korra, Late Stage RWBY nonsense, where they realize that all they have left are the shippers, so they pander hard.
Also, unless that river is cutting through pure rock, don't rivers change their course over time unless maintained by modern waterway management? It says a lot about how disinterested I am in this story, that the idea of a river with an unchanging channel bothers me.