Lots of questions, few answers.
Informed speculation:
The RSR and lesser Coco attraction pitch was likely a product of then uncertainty of the IPs for Dinloand's makeover. This is where the Coco carousel originated.
I believe the additional, post-Dinoland AK expansion might be an either/or with the rather new momentum towards further DHS expansion.
I expect Moana and BBTM sitework to happen in tandem, shortly after work in AK begins. My gut still says Coco as the BBTM phase 1, with either Dark Kingdom or RSR going to DHS. I still lack confidence of a BBTM phase 2 coming to fruition in a timley manner. With a total of just 14 acres in play, that doesn't create a spectacular amount of space with their current layout.
And, while we're here, I've heard nothing but blue sky nuggets about additional park entrances, onstage hotel options, etc. Despite all the other "original" directives they've abandoned at MK, the arrival progression is still very much hallowed.