I feel like after reading this forum and the press release I think it will be based on the Triwizard tournament. Being that the queue is rumored to be staying and as it appears in construction photos it is. Meaning nowhere in the forest is castle structure mentioned. Also being that there not expanding Hogsmeade that wall for the ride will either stay or go. But then where will you enter the ride without it being hidden. Also based on the press release it mentioned creatures and the only other place in the story where creatures are in a higher quantity is the tournament. Mermaids and dragons.
Also in the press release, it mentions thrilling places. Graveyard, maze, the lake. All of which are places that make sense in the setting of the ride and the other facts stated above. For a while now I had the idea that they could put a maze ride and have it end in the graveyard scene. A while ago they filed a patent for wands or some type of device to control a ride and the path you take, I doubt now knowing it's a coaster this will be part of it, but who knows.
Also, this type of story allows the viewer to view Harry and the characters from afar, and they would be able to use audio from the films. They might not want to repeat the dragon from the forbidden journey so they may show for the first time the other dragons. Also, we could see the ride from the other champions perceptive, until the end where we would see Voldemort in the graveyard. The only problem is why is the rider put into the story, who is telling us in the queue what is about to happen. Hagrid or Moody could be an option, or maybe a show scene reveals it more during the ride.
For effects, I would be surprised to see mermaid coming out of the water at the car, if that's even possible lol. All of this is my opinion, who knows it could be the forest but I think it would be harder to pull off being that it would require an entrance not located where the current is.
This is a good guess, but technically, they don't have to follow any particular storyline from the series verbatim. Forbidden Journey certainly doesn't . As for magical creatures, there are so many to choose from: Aragog, the basilisk, Buckbeak, centaurs, dementors, dragons, Fawkes, Fluffy, Grawp, the giant squid, grindylows, mermaids, Nagini, thestrals, unicorns, werewolves, winged horses, and maybe even a nargle or two.
As for places, there's definitely the lake and the Forbidden Forest, but we could also see the Shrieking Shack, the boat house, Aragog's cave, the owlery, Hagrid's hut, the viaduct, the quidditch pitch, as well as any number of places we could apparate, portkey, or travel by floo powder to.
I do remember someone mentioning once that Hogsmeade is generally set in the earlier books, while Diagon Alley is set in the later ones. If that holds true, we're much more likely to see the Triwizard Tournament than Grawp. Anyone know if the early vs. later books distinction still applies?