If two creatures are blinded (such as by Fog Cloud or Darkness), does the Adv and Disadv cancel from both?

@zeanrivera @JeremyECrawfordIf two creatures are blinded (such as by Fog Cloud or Darkness), does the Adv and Disadv cancel from both? yes

— Mike Mearls (@mikemearls) January 31, 2015