I made mention of that, or at least I thought I did. He said the hardest tape for him to get a grasp on is Williams, because he doesn't like the offense and their O-line caused issues, but when looking at them play QB and playing in schedule, playing in the pocket, making certain throws, etc, he said that Penix and JD5 consistently had the best tape. He felt Nix and Penix were the most accurate.
Honestly, what he said is the tweet you posted is why I don't get the "generational" title being thrown at Williams because nothing that he does or have done really points to that. Not saying that he isn't good and can't be great but he probably really only got that title because of playmaking and not quarterbacking, and sometimes, it feels like he is forcing it. If he indeed goes to the Bears, at least he will be in an infinitely better situation that what his predecessor had to go through.