This is assuming Gobert is on the supermax deal he's eligible for and Mitchell is on a max. Conley's contract expires before the 2021-2022 season. Horford's runs for two years longer and this an approximation of what happens to their payroll if they have Horford on the roster. Horford will also be 35 and 36 years old in those years.
This projection is also assuming they fill out a bench with 5 players on veteran minimum deals. That would totally deplete the bench. In the 2022-2023 season it gets really bad because then the Jazz would likely be repeat offenders on the luxury tax if they weren't already.