Gender locked race?

[Nestama]

They could fit male Viera easily in the lore if they say something like "the garleans violently cleared forests, and many (male) Viera had nowhere to go, and became adventurers.

I think they specifically live in one forest (or just that one area), so probably won't do this. Also, SE have not once given player characters a past/history to give them a reason for why {race} is there (take the Au Ra who Yugiri doesn't even acknowledge, for example). Where your character came from, why they went to {starting city}, etc is up to the player.

If SE made it so my Roegadyn left his home at 18 years old to visit {starting city}, I would be very unhappy with SE. He's clearly in his early 40's (underneath that Behemoth mask) and wishes he was really a Galka.