[Brekkie]

It's not announcing the decision that's needed, it's the explanation behind the decision - and you get that by hearing any discussion between the ref and VAR.

Guess the difference with the TMO in rugby is that the ref usually calls the TMO into action and in recent years it's evolved into a communication between the two, whilst the VAR seems to automatically come into action and its only if the ref goes to a monitor they're nothing more than the messenger.