Agree that Belichick in general has become more conservative on 4th down plays; it was noted several times last season.It was the later punts I was referring to, and using the result of a one-off play is a terrible way to judge a decision-process when you have mounds of data that can inform you. Particularly when that result is obviously an outlier.
If those later punts had been an atypical Bill move in reaction to the game situation I wouldn't mind so much, but they're not. They're quite typical of a coach who has been very much on the conservative end of the scale in recent years.
However, these 2 plays do not necessarily reflect that. The first one was a 4th-and-9 from Pats territory; that is a punting a play, and I really cannot criticize them for not audibling to a fake. Reiss noted that Bailey did change the direction of the punt based on the free release of Schroeder. The calculus on the later punt is a bit more nuanced; it's probably 50/50 whether the team should go for it there. However, the raw numbers ignore how poorly the Steelers were playing on offense against the Pats defense.