It could be. First off, I have no idea how the fantasy football stuff works, and don't want to. On the other hand, if it's anything like actually odds making, popularity counts for a LOT. Sure there are various factors as to who's most likely to win, but the odds are also set by which one people are betting on. Let's say statistically there's a 50% chance that team A will win, and the betting odds were at 2 to 1, if 80% of the people were all betting on team A, the bookie is going to lose his shirt if team A wins. So he increases the odds for team B and decreases it for team A to induce people to bet differently. That way, the bookie has the monetary edge no matter who wins, which is good business for him, and gambling for you.
So if these fantasy football things are similar to sports betting, they are tweaking the numbers based on popularity, they'd have to.