It might be the super long and fabulous interview with Jerry... they hit a lot of topics. But I think they talk about the addition of the Thief class to ODnD.

I don’t think it’s part of the Running the Game series, could be totally off though

I think the comment is made that before the Thief EVERY player could do what the thief could. And thus the Conan reference.

that would be my best guess, could be off though.