This all started week one of the season against Detroit, the announcers were complaining the entire game about how far back and how quick the tackles were going on the count, and the drops started also.
The league and refs were embarrassed that the not being on the line was not flagged, and have hammered the Chiefs since then. The Chiefs get little benefit of the doubt and get called on crap now that most teams get away with.
Watch the offensive tackles on other teams, lots of them leave a split second early, but when the Chiefs now do it, the get rang up.
It all came together last night the drops, flags and the rest of it and Mahomes and Reid just went off, good for them. Sometimes you have to show the league that you are only going to take so much of it without saying anything.