no he did say that the major patch will have a time between each of 2 to 2 and half month.
and while the last live letter he did say that the 2.1 can arrive sooner than player can expect it.

and that all... no date.
my bet, still, will be around 15 october, because let's be honest, the game need more feature actually, it's true that we have ton of class at level up and stuff to get by running the same dungeon a billion of times.
but i guess it's will not be enough to keep people hooked, if he was smart, i will have the 2.1 for the 27th september, right 1 month after the release.