Incorrect - we were expected to know them all, and I heard "give me the Leadership Traits in order with definitions - GO!" during RLP. Its not hard to learn them all before hand - make flashcards, review every night, and you'll have them memorized in a week.
I mean, if people waiting for OCS already have the Navy/Marine ranks (officer and enlisted) down
perfectly, with all pertinent devices, and can recite the articles of the Code of Conduct and General Orders verbatim, and can sing the two service songs (melody and all), and know their Chain of Command perfectly, then sure, go ahead and study those leadership traits. Since I'm assuming nobody has all that stuff 100% yet, I'd highly recommend spending the mental energy on reviewing the aforementioned items. Even
if the DI/Chief asks for those traits during 3rd-week RLP—and that's a huge
if—the resulting hit won't be the deal breaker. But most likely, they're not going to ask for it. I graduated recently and haven't ever heard of the leadership traits being brought up during RLP. I
have seen people take on multiple knowledge hits for missing the crucial items, though.