I agree with your theory...pretty solid logic!
Just a couple notes of interest:
I doubt that they'll be developing an all new engine, like you. But it's not impossible that they would modify one for this specific application, (ala L99/LS3).
The SS is already equipped with FE3, and the magnetic ride control and driver-selectable ride control is one in the same. More than anything else, I want to see this system in the car.
If Ford can get the GT500 a rating of 16/22...dang it if Chevy can't at least match that.
I really don't care what
it is...so long as the price is right, I'm just overjoyed that the Z is coming back!!