That might be because they cleaned the dataset thoroughly. I vaguely recall there was something about 'facial landmarks' and alignment in the ProGAN work which was presumably carried over to StyleGAN. Doubtless helps the final quality.
However, aligned faces are definitely not required - I didn't do any kind of alignment for my anime faces and you can see the eyes/nose/mouth in all sorts of positions in the samples & videos.
However, aligned faces are definitely not required - I didn't do any kind of alignment for my anime faces and you can see the eyes/nose/mouth in all sorts of positions in the samples & videos.