Idk what the NFL will do but I'd almost guarantee the Bills won't have to forfeit. I see no way the NFL "adds insult to tragedy" by giving the Bills a loss in the event this game isn't played. If anything I would think they would use 2020 protocols and base things on winning percentage if teams didn't play the same number of games. I think they would simply treat this game as if it never happened and the Bills/Bengals will play just 16 games.
We do know it won't be played this week, and it shouldn't. Why make the Bills/Bengals play tomorrow then have them turn around and play Sunday? It would already be an increased injury risk with the short turnaround, then add in the mental fog those players will be dealing with and it's a recipe for more disaster.
I'm the first one to criticize the NFL when they screw up but so far they are handling this well.