The thing is, the refs have been miked up for many years now. But their conversations remain secret. For the last 20+ years at rugby internationals you could hire a radio device that was tuned into the refs mike so you could follow the entire match. They often broadcast the ref's explanations on the tv but refuse to do this for football.
Also, they show the TMO (VAR) replays on the big screen in the ground so the 3 refs and the TMO can all watch together (along with the fans, players, coaches, tv audience, etc) And you hear all of the refs chatting through their decision. This is much clearer to evrryone but for some unknown reaso the football lawmakers refuse to allow this.