He missed two games and played hurt in 2014. The better season to compare to is 2013, when he played 16 games and threw 24 TD passes, his previous career high.
In 2013, Cam's TD percentage was 5.1%, in line with the rest of his career. In 2015, he led the NFL with a 7.1% TD percentage. That is a huge jump, and it seems unlikely he will sustain it.
If you look back over the past decade, all of the leaders in TD percentage dropped off the following season, sometimes very significantly. You can also look at it another way. Rodgers has only been at 7.1% or better 3 times; Brady only 2 times; Brees never; etc.
So his TD passes seem very likely to drop back under 30 unless his pass attempts go up significantly, which seems unlikely. Combine that with the likelihood that he will not rush for 10 TDs again, and his fantasy production seems likely to regress by a fair amount this season.