The UFC has a PPV scheduled in Los Angeles on August 2nd. The main event was going to be Jose Aldo vs. Chad Mendes 2 but Aldo has withdrawn. The co-main is a pretty excellent middleweight bout between Jacare and Gegard Mousasi but those aren't guys that are going to sell PPV's. Rumour has it the UFC is scrambling to put something together for a main event -- possibly Ronda Rousey vs. whoever will fight her. There is a more dubious rumour that the event could be cancelled.
Re: UFC 176 has no main event It is in LA so he would have a semi "home-field advantage" put him against Rory MacDonald or Saffiedine and you have a kinda-sorta main event.
Fights from this card will be moved to other events. I don't know if the number 176 will be a lost PPV or if they will push back the numbering on future scheduled cards.