I'm guessing more a function of how bad his first 3 weeks were, particularly the KC game. His QBR last week was 69.1 and this week 77.1. Over a full season, those numbers would be 6th and 3rd in the league respectively.
Edit: His first 3 weeks were 21.6, 24.0 and 17.2 which are all worse than Bryce Young's season average.