Scream no, but I still think there is a reasonable chance he ends up with over 20 this season, provided he stays healthy. If you combine both regular season and playoff last year he scored 30 in 81 combined games. Now, you are right about the shooting percentage, and we should expect it to regress. However, if he's plays all 82 games, I would hope he breaks 20.
I guess it comes down to if you think his last season was just an outlier, or a step in development for a not that old of a player. Most likely it's a bit of both, but personally I'm leaning more towards the latter (although It might be because of these rose-tinted glasses I'm wearing).