He did it like 2 times in the Bengals game, he also showed he can go through his reads. Peterman hits the back of his drop and the ball is out, unless the guy is covered. I'm not even sure this is up for debate plenty of people who watch the Bills comment on it. He knows where he's going pre snap. So defenses will play more Zone with him so they can watch where he's looking and break on the ball.
Look, I'm not saying they won't stack the box and stop Shady but if you don't think they would plan differently for Peterman vs Allen, who's shown he can go long, I'm not sure what to tell you.