They've mentioned November, but who knows. Perhaps late this year or at the beginning of next? Some changes must be easier than other, or compared to completely new models; but still, a new engine is clearly more complicated than rearranging the lights at the back or similar in a new MY.
They do seem to have their hands full now;
with the new Roadster, the new +8, the three-wheelers, the Aero SS still in production, the limited 75th anniversary 4/4, and the +4 SS, though perhaps finished, and all on top of other production and also the EvaGT. They must be quite busy nowadays.