The Cowboys were also supposed to get blown out by Tampa Bay in the opener, had no chance against Carolina's defense in week four, would get humbled by Bill Belichick in New England, were mailing in the Vikings game by starting Cooper Rush, would roll over the Broncos at home, and rebound against the Raiders on Thanksgiving.
What am I getting at? The games have to be played. We have no idea what the Cowboys' chances of beating Green Bay are. We're making assumptions based off the current level of play by both teams. Things just don't stay the same in the NFL.