Multiple sources report that Mauro Ranallo will be returning to the NXT broadcast booth tomorrow night.
He had originally been slated to join the rotation of calling matches at Survivor Series; but after a tweet by WWE color commentator Corey Graves, Ranallo did not work the event and deactivated his Twitter account. WWE's cover story on Survivor Series was "that Ranallo had blown out his voice at TakeOver and would be back that following Wednesday". However, Tom Phillips filled in for him instead.
Graves apologized on his WWE-produced After The Bell podcast, claiming the tweet, which has been deleted was designed to play into the brand supremacy element of Survivor Series, and that "he was going to bring it up during Survivor Series as part of the brand supremacy angle", which sounds like an after the fact justification; since he never bothered to tell Ranallo this.