He has not said anything remotely close to coming out and completely bashing the Bills like he's done previously - not the QB, coach, or the other players.
He has made a subtle comment here and there - said the team could have a winning record now (which is the truth) - acknowledging they lose games in the 3rd and 4th quarters. Comments revolve around being double-covered - meaning the QB may not have the confidence to throw to him (this is true - especially with 3 rookies on OL and 4 of the 5 never started an NFL game before the season) and the large # of injuries.
I'm not sure exactly what you heard, but he hasn't had a full-blown blow-up on the team . . . yet ;-) He's had little comments here and there, but nothing like he did in San Fran, Philly, Dallas - and nothing really bad. Admitted his stats are pathetic and that he's frustrated. Only people he's criticized were the media. Some fans would LOVE for him to come out and say - "We need to keep Fitzpatrick in and need to bench Lynch. We need to quit running on 1st down and need to have plays that include 3/4 wide outs, etc."
Like I said previously, he could very well have one of those blow-ups in the near future, but he hasn't yet.