It seems really unlikely to me that they will retool the rear door or the body section between the rear doors and the bumper- that would be really expensive for a low volume car. And with the wheel opening so close to the rear door, I don't see how they could add on a separate flare or wide-body element (like my old Renault R5 Turbo) that wouldn't look ridiculous. I suspect the only things that will be different from the normal Corolla on the rear will be a bigger roof spoiler and a more dramatically styled rear bumper.
Also noticed that the most recent tease has no indication of bulges fenders either front or rear.
Also noticed that the most recent tease has no indication of bulges fenders either front or rear.