Well, we're all working from inference. But using deductive reasoning, why would they reroute traffic transiting to and from Fantasyland and Frontierland into SWL? It's not like they will need to force people into the most popular land Disney has ever created. It would be like closing the walkway between BlueSky Cellar and Little Mermaid, forcing all traffic to go through CarsLand, the most popular crowded area in DCA.
I don't have any more information than anyone else. But it just doesn't make sense to me. Throughout Disneyland's history there has consistently been more connectivity, not less. Originally it was literally a spoke layout and all traffic between lands went through the hub. Even the opening between the entrances of Frontierland and Adventureland didn't exist. WDW MK introduced full connectivity in 1971 with the connector between Fantasyland and Liberty Square before Disneyland achieved that with the new Fantasyland and Big Thunder Trail.
I just don't see them giving that up. SWL is going to be wall-to-wall people, so I don't see why they would need to force more in.YMMV.