I'm of the opinion they could still make a playable void race and fit it in with the lore if they really wanted. There is already voidsent humanoids in the game that are enemies. Surely there could be a reason that not all of them are innately evil and are capable of thought process, emotions, or can feel the compassion from adventurers.

It is eventually revealed that the Void was originally one of the thirteen mirror worlds that were created when Zodiark was defeated in ancient times. On this world, the powers of light were defeated and it was completely consumed by darkness, transforming it into the Void.
Surely the humanoids from that world can be touched by the light again in eorzea? I dunno, just throwing out my two cents. It could work if they wanted it to.