While I can't say for 100% sure, the artwork/mock-ups we've seen for the cover of the three core books certainly look like "normal" RPG books, not square.
No, it's not. Same thickness; shorter in height, yes, but wider in width. It takes up just as much space overall, doesn't match any other book on the shelf/in the pile, and (IMO) is harder to read.
If the book were actually smaller, and still contained the same amount of material, I might agree with you. As it is, I pray they never even glance at a SWSE-shaped book again.