Here's an article concerning the Diamondbacks. Nowhere is OTA broadcasting mentioned, nor will it likely ever happen again, at least not in Phoenix.
Despite Gray setting up a sports channel (albeit one with a very small signal), the D'backs left OTA in 2007 (English) and 2008 (Spanish). The current ownership has had zero desire to offer their product for free. I'll be absolutely shocked if Gray, or Scripps for that matter, get OTA rights for the D'backs or Suns, and only a slim possible chance for the Coyotes.
MLB will aim for fans to stream games for free if Diamond Sports Group, which operates Bally Sports TV stations, loses its rights.
arizonasports.com