Pedro Gomez of ESPN reports that, starting this season, umpires will be mic’d up and will announce if reviewed calls are upheld or overturned. Gomez adds that they may also explain rules, if necessary.
As it is now, umpires just get on the headset, get the replay decision and then signal the call non-verbally, be it safe, out, or whatever. Fans watching on TV or listening on the radio then get an extended explanation from the broadcast crew about what happened. Or, quite often, an attempt at an explanation, starting with “well, apparently the replay official saw . . .” or something like that. Now it’ll come straight from the crew chief’s mouth.
Joe West is a crew chief, by the way, so if you were worried that he did not get enough screen time before now, he and his colleagues are about to get more.