It would be a disaster for spike and ufc if it did. Not a total catastrophe, but the point of the season would be essentially ruined, and they'd probably lose some viewership and public attention- and that means $$$.
So undoubtedly each figher's contract includes very very harsh language about what happens should you divulge that information prior to its airing. Given their speculative damages it could be in the millions and would likely additionally guarantee a barring from fighting in UFC and Pride, which means mainstream MMA is gonna be a pretty rough career.
So while it's a definite possibility to happen sometime in the show's lifetime, I wouldn't count it. It would be idiotic.