Gender locked race?

[Nestama]

I can't really see male Viera being short and "young Elezen" in appearance. Wouldn't they look more feral due to living in isolation and, depending on what they do, maybe buff?

Honestly, SE should have just given the Viera lore completely unrelated to FFXII's (I would still prefer they weren't going to be playable in this game at all). The way they wrote the males is far more restrictive than the male Miqo'te (I imagine male Viera who stray from their duties would probably be hunted down by their own kind if they stay/enter the Great Wood).

[Senn]

...

Apparently, there's going to be a variant that looks sort of like a "young elezen". Sort of, not exactly like. So who knows.
Whether this variant is going to be male viera or if viera is going to be female only, no one knows. If it's female only, then the variant will just look similar to a young looking female elezen.
Personally, if the male is the "young elezen" variant, I can't imagine they would be bulky. It's possible they can still look feral, even if short and slim. I think they would retain some of the same kind of grace the female viera have.