Also consider that the Jazz have only been outscored by a total of 525 points this season. That's only 6 games worth of points. Let that sink in for a minute. 6 games off the .500 mark is 38-44! So their current record is not representative of how well they've actually been playing.
Okay bordy, this is what I found. The Jazz rank 6th to last in RPI. If you use the average win % after the first 15 games to adjust those first 15 games up by 4.5 wins then the Jazz probably move up in RPI to around the teams playing 43-44%. Considering I said they were playing more like 46% ball (unadjusted for RPI) before they went 2-16 or whatever, it wasn't so preposterous to say they were already a nearly .500 team next season through growth of Trey, Hayward, Favors, Burks, and creating a properly formed bench through free agency.