I didn't read any articles announcing this VAR change, I just presumed from the titles alone that the whole point would be to explain why a decision was made. I suppose there's not much explanation to give for a handball penalty except 'there was a handball'. Maybe the more complex VAR reviews will see the referee talking us through the outcome, if not today then in the future once the whole thing has been ironed out.
It does seem to be designed for the benefit of the fan inside the stadium, rather than at home. Which makes sense. Though it might be better for the fan at home if the TV feed provides direct audio of the referee's mic instead of having us listen to the decision via the stadium PA. I really couldn't make out anything that was said except 'penalty' and I could gather that already from the hand signals.