I don't think the term Unix ever became generic at all, so unless Apple can come up with a better excuse, I hope they lose this one.
Why? Because Apple are blatantly using the name "Unix" to appeal to corporate decision making types. If they wanted to be accurate, they would be using BSD, but that doesn't carry the same weight as "Unix". Therefore, as Apple are using someone else's trademark purely for advertising purposes, it is right and proper that they should pay for it or remove it from their documentation and promotional material.
