No.
Superdelegates make up one-fifth of the delegates at the Democratic National Convention. So, 747 of the 5,083 delegates attending the 2016 Democratic National Convention can choose whichever candidate they prefer.
Out of 2,470 total delegates at the Republican National Convention in 2016, 437 are unpledged delegates, who play the same role as superdelegates. Of the 437, 168 are members of the Republican National Committee