My only objection to your theory is that the lips look more female in that style. But given we don't know what male Viera look like, that's not necessarily a valid objection in the first place, before being a personal observation of mine. And now I'm slightly hyped.
It being a Viera at all, least of all a male one, gives more reason for them to keep that chara hooded and shaded than any other plot reason could XD