This is a misunderstanding. The broadcasters can hear the conversation between referee and VAR, they can't speak to them.
Someone's gotten confused in how Dixon has phrased it, thinking Dixon means he, Lee Dixon, asked instead of he, the VAR asked.
Or he's talking about the broadcasters sending queries to Stockley Park after the fact to clear up decisions. They can ask them what the reasoning was, if an incident was looked at etc. Which is how we get situations like the one where Stockley Park admitted it was a mistake for Coote to not send off Lo Celso in a match last season before the match ended.