The Buffalo Bills hired Ken Dorsey as their quarterbacks coach in 2019 when David Culley left to join the Baltimore Ravens. This offseason, Dorsey received a promotion with little fanfare and the team never announced the move. His bio on the Buffalo Bills website now says passing game coordinator/quarterbacks coach.
Passing game coordinators take a larger role in the offensive game planning on the field and in meeting rooms. They also get a pay bump. This is also a pretty clear indication that if current offensive coordinator Brian Daboll leaves to be a head coach somewhere else, the Bills have a succession plan in place.