Or we're just mistaken about where Star Wars land is going… Or what's happening to Muppets… Or any number of things honestly
I think is is a major factor. Based on the concept art, it's pretty obvious where TSL will be going (mostly on "backstage" area not currently open to guests, so it actually IS an "expansion"). Disney has said nothing (at least to the best of my admittedly limited knowledge) about where SWL will be going. There have been many (possibly nhilistic) assumptions that it will wipe out the entire Echo Lake area, but do we KNOW that?
What's to say that ST won't be at the entrance to SWL and it will build back to the LMA, SoA and backlot tour areas (and possibly wrap around to the Indy area and into the parking lot). A crescent-shaped land actually makes for better story-telling than a large rectangular "chunk", because, paraphrasing Walt, you have the weenie at the end drawing you further into the story. If you look at almost every "land" in every park (FW being a notable exception), they are essentially linear. Carsland, often cited as the "best" land that Disney has created is an extreme example of this; a single perfectly straight street with the rockwork to draw you through. Hollywood Blvd - a straight street with the Chinese Theater to pull you through. Sunset Blve - a relatively straight street with ToT to pull you through. Echo Lake, although curved, is a single street with the Indy billboard and Gerti to pull you around, and then you see ST which pulls you through the rest of the loop. And in all of the above cases, shops, restaurants, and lesser attractions to keep you accupied and enhance your "immersive experience" as you pass through. Where does the design of DHS fall apart? When you get to SoA that has no linear flow and no major archetectural elements to draw you in/through (which makes sense as it was originally part of the tram tour and not an open pedestriam area).
I would think an ideal design would be to have ST right near the entrance to SWL, put one "e-ticket" roughly where Indy sits, the other roughly where LMA sits, and have a long. narrow, "land" connecting the two. And IF one of the 2 e-tickets should happen to be a coaster (a guy can hope, can't he?), there would be plenty of space in the Castrophy Canyon area to house it, and it would be largely unseen in the rest of the park And if rumors are true that the WDW and DL SWLs will be built on the same basic footprint, take a look at ToonTown; a large crescent-shaped land where you enter in the middle, have RR to pull you through in one direction, and the treehouse and coaster to pull you through in the opposite direction.
Yes, more speculation and "armchair Imagineering" - but isn't virtually everything we have regarding SWL - other than 2 pretty pictures and a few vague comments - just that?