The thing with Grayson is that he was a very efficient scorer last year under duress. He shot high percentages while being keyed on by opposing defenses, with his team needed him to score, and with very little rest. Other teams also played him, and Duke in general, very physically, knowing Duke couldn't respond in kind due to depth issues.
I could see him averaging similar pts per game this year with less field goal attempts. Hopefully, he shoots even higher percentages due to more rest and defenses being less able to key on him. Additionally, with Duke being so loaded and likely to be ahead at the end of games, he will get even more FT attempts, which would also make up for possibly less field goal attempts. Last, Duke should be a better rebounding team and more able to apply pressure this year. That could lead to more fast break attempts, where he is lethal.
I could see him averaging similar pts per game this year with less field goal attempts. Hopefully, he shoots even higher percentages due to more rest and defenses being less able to key on him. Additionally, with Duke being so loaded and likely to be ahead at the end of games, he will get even more FT attempts, which would also make up for possibly less field goal attempts. Last, Duke should be a better rebounding team and more able to apply pressure this year. That could lead to more fast break attempts, where he is lethal.