That logic works both ways. Did those same predictors say that Georgia would beat Alabama in the first game? You can't just ignore half the results and point to the remaining half as "proof" of validity.
Did these predictors say that KC would beat CIN in the regular season last year? How about in their AFCCG rematch?
I'm not saying anything about the degree to which such predictor variables are accurate -- I'm merely saying there are variables in that regard
more accurate than team win percentage over a relatively small sample of games or the result of a single previous game between two teams.
Consider that right now Buffalo and the Giants are both 2-1, yet the expectation would be for Buffalo to all but trounce the Giants. That expectation has to be determined by something other than their records. And if they actually played, the Giants might win the game, but if they played again the following day Buffalo would be favored again nonetheless.
It helps to pan back and ask yourself which team would win the majority of games if they played 100 times. If the Giants played Buffalo and by chance beat them, and that represented one of the perhaps 10 times out of 100 they would beat them, well then Buffalo remains clearly the better team.
Again none of that matters in terms of who reaches the playoffs, because there again we're using team records almost exclusively -- this pertains again only to which variables are best used to determine the better team and the one
expected to win.