Diaz has been on the fast track at Viacom. She was elevated to her position last fall—her second promotion in six months—where she’s been stewarding the unscripted business for MTV and VH1 as the networks cement their core DNA under Viacom chief Bob Bakish. And she’s been busy. MTV is downsizing its scripted presence and moving even more strongly into unscripted programming, focusing on series with strong, buzzy reality characters. VH1, meanwhile, will also continue to air an amped-up slate of unscripted shows, including music docs and the recent expansion of its top-rated Love & Hip-Hop franchise with “Love & Hip-Hop: Miami,” slated to debut in January.