Gender locked race?

[Alesone]

I think that's a different issue. Male Viera are made (potentially) unplayable because of their individual race-lore that states they don't go out of the forest.

No, Male Viera are potentially made unplayable because of the decision of the director of the game. Whether it's his personal hangups in finding them unappealing, or his desire to put in a male player race that he thinks people would like more, or that he likes more. The lore has little to do with it because the lore can always be written to accommodate their development decisions.

Garleans and beastmen aren't playable for world-lore issues. Both would make for particularly awkward storywriting when the Warrior of Light is "generic" and the script is the same regardless of race (except for the occasional nod) as their races are in direct conflict with the protagonists.

Except for all the ones we actively work with? All the Garleans we've now associated with, some of which were direct enemies before. All the Beast tribe quests we undertake that deals with members of those races who are in no way in direct conflict with us. There's absolutely avenues the devs could take to make these things playable, but the reality is they can't or won't. Those decisions come first, and the lore is made to adapt to those decisions. Same thing with male viera.