The NY Times (and me) think this was a mistake:
Teams have made around 48 percent of their two-point tries in the last three seasons. If you factor in that teams made around 94 percent of their extra-point attempts this season; that home teams tend to win overtime games (by a slight margin); that favored teams tend to have an advantage the longer things play out (Green Bay was a 7-point underdog); the math is on the side of boldness.
Probability of a win=Prob[kicking extra point]*Prob[winning overtime]=94%*45%=42.3%
Probability of a win=48%
NOTE: I do not know how frequently away teams win overtime games, but assumed that it is 45%. The article suggests only some number less than 50%.