In every format of cricket the tiebreaker should be added to the coin toss. If you win the toss you should be able to choose bat, field or win in case of equal scores. If you choose bat or field, tie goes to the other team. If you choose tiebreaker, the other team chooses to bat or field first.
Cricket is the only sport where the coin toss moves the line.
It should also be added that New Zealand winning the coin toss in this past Summer’s World Cup Final gave them an edge sufficient that they have no place to whine regarding the arbitrary nature of England winning the super over tiebreak via boundary countdown.