Since this has come up organically, I don't feel bad throwing in my two cents, though
the previous thread demonstrated this to be an unpopular opinion here.
Kurtzman has explicitly followed on from the canon policy of the JJ-verse inasmuch as they changed what was considered canon in Star Trek from what it was during the Roddenberry/Berman era. They then made prequels and continuations. They are, therefore, not exactly prequels and continuations of the previously existing universe.
So no, you will get no direct statement that it is an alternate universe, not only because that's a mortal sin to transmedia marketing types, but also because it isn't an alternate universe from TOS,
to them. The new, modified Star Trek Universe they've created includes "original universe" works like TOS . . . it just also includes novels, comics, et cetera.
The prior universe, which I call the Original Universe, remains untouched and pristine.
Thus, I for one have no concern about SNW dovetailing aesthetically into the original TOS look, because it doesn't have to. Indeed, the recent news stories suggesting that the end of SNW suggests no follow-on TOS show actually makes me sad because we won't get to see the lack of TOS aesthetic contemporaneously with the stories shown in the 60s (and after) . . . because you
know they were never going to rebuild the TOS sets for that.
Because for some people the "Original Aesthetic" will always be the "Correct Aesthetic".
Televised storytelling is an audiovisual experience. Changing the aesthetic wholesale *is* changing the story, especially alongside other modifications to the existing tales. Take the same Trek audio and make the show's visuals AI steampunk and it isn't the same any more than playing some other audio atop Star Trek visuals makes for the same show.
But, if you like the changes, enjoy them. IDIC!