Since they have won the final match they definitely deserve to be the world cup T20 champions - However there are teams who are much better than Australia in terms of Balance, Talent and potential. But the key to win this tourney was winning the Toss (as I watched in all matches)
Toss plays a huge role in T20I'S in UAE due to DEW. Win the toss and field first is the secret of winning 60% match before the ball being bowled.
First Batting team will struggle with timing since ball will stop and come and bowlers will have better control of the ball and their variations will be effective. Whereas in second innings batsman can score freely, ball will skid nicely on to the bat due to dew and bowler will find it difficult to grip the bowl, Most of the times ball will slip out of bowlers hand.
Best Example: Md. Hafeez Double bounce ball to Warner in Semi finals.