Don't be surprised if soft openings happen a lot sooner than Nov. 19th (my b'day, BTW). I think they will begin moving the walls back one attraction at a time from Enchanted Tales to Little Mermaid. Enchanted Tales may soft open as early as October. Pathways and landscaping are ready. Just have to train cast members.
The DL Cars Land opening seemed like a mess because of crowds and attractions going down. RSR was down a good portion of the day in each of the first couple days it was "officially" open. I can't imagine that Disney would use that as an opening template unless they had no other choice. By the looks of things, they do.
Soft opening one attraction at a time, unannounced would give time for word to spread and crowds to build slowly and steadily. There's no way that Disney is going to bank on opening on a specific date without plenty of testing. Imagine if there were undiscovered safety issues on Little Mermaid that forced them to adjust some ride specs. Those changes could force them to miss the "official" opening date and then people would complain and Disney would have a lot of explaining to do.
When Dumbo, Barnstormer and Casey Jr. soft opened people showed up one day and the walls were gone--no announcement and well in advance of their official opening.
I'll be surprised if we don't see some of these areas soft open in October. That's still 2 1/2 months away. We'll see.