People have DVR"s now, so they will watch both fights.
This fight is on ESPN so no need for promotion, everybody watches ESPN it's the biggest sports Network on the planet and Disney holds a controlling 80% stake in ESPN.
So why waste money on promotion. Everyone who loves boxing will watch this fight and everyone who is a casual fan will watch this fight and MMA fans will watch this fight, because this fight is on ESPN and that's free tv no need to buy HBO or Showtime. ESPN is everywhere and no need forking out 99$ for PPV.
This fight will do just fine Bob doesn't need to worry about viewers because ESPN already paid him the money to show the fights on their network and ESPN is not worried because it's freaking ESPN they got money, crazy mad paper.
So chill, kids everything is ok.