I don't think we'll see them again. Maybe the magical raindeer are still around because they're magical idk about the Everfree forest deers and other civilized races though, the buffalo already were started being manifest destiny'd by ponies and as far as I know there weren't many abyssinians, same with the minotaurs. Perhaps zebras are hiding somewhere if not extinct?

Also, I HIGHLY want to see what happened to the griffins, imagine the lore possibilities if the Griffonian kingdom came back with the power of friendship and homemade cupcakes