>>15292308X and Y means both.
They obviously were playing around with the fact of dimensional planes considering that this is the first main Pokemon title on the 3DS, and that it is the first Pokemon game to be in full 3D. The fact that Zygarde is in it indeed points out that this was one of the references with X and Y.
However, they were also talking about genetics. In the japanese logo, you can see a strand of DNA on it. This is in reference to Mega Evolution, as the same DNA logo is on the Mega Ring.
It's talking about both, people.