Well.... I don't see it.
They are again the same cars with different front ends. Which is pretty sad, Which also means that, again, the Escalade will just be a Chevy with a Cadillac front.
Inside, at least, it is not like the 2014 Chevy trucks. But look! The column shifter is still there! In a 2015 model.
That's pretty amazing. (And sad)
I guess GM doesn't really care, since they keep selling tons of these every year. Over 100 000 of them last year alone. Without including the Suburban and its Yukon KL twin.
So, I guess they're right... Why bother making these modern and different from each other.