Again, you are reading way too much into it. He's simply saying he doesn't know how are KO works. He's not suggesting he doesn't work hard enough; he just doesn't know.
That's like me going into a restaurant and saying, "well, I don't know how well this chef cooks" and suggesting the food is crap.
But, to keep with your argumentative nature, let's look at the 2nd line of the sentence you didn't address.
"If he comes in a works as hard as Miles Austin worked, then he’s got a real upside."
That, to me, suggests that he sees what coaches saw in MA a few years ago. A lot of talent that needs work. KO has the talent. If he continues to progress as MA did, he will be a good WR for the Boys.