Jazz have a lot of variance because of their personnel. The team saw a lot of players take on new roles and opportunities. That should compound this year with a prospective new starter in John Collins and multiple rookies in tow.
The league will also see a lot of variance due to a large middle-class. Half the league was separated by 10 wins (Jazz at 37 to Knicks at 47). That theme figures to repeat this coming year with many of the bottom teams looking to make a jump and few, if any, of the middle class falling to either side.