If the model is just ripped from FFXII, then that tells me Viera aren't planned to be playable. If they're actually given a new model (built from the ground up), then we can use this as proof they'll probably be playable at some point. I will do my best not to say "I told you so" if I see any Viera supporter state their disappointment with whatever design SE go with (and I still doubt they will have the same lore as XII's Viera). I'd be very disappointed if it's just a human with rabbit ears no taller than a Midlander, though. Surely SE have the funds to at least try.
All that said, regarding your "Not to mention that many who want said "diversity" would not use the races in question" comment, I would play as a Lupin were they playable. Or any beastman, really (when I was a Roegadyn, I
fashioned this look for a few months. It did not look as good on Lalafells)... except the Sylphs, Moogles and Namazu.