Why would a new owner move the team? The Jazz have been top 10 in attendance for as far back as I can find the attendance data. And since the DC/ESA was built they've averaged a minimum of 18,332 people a game. For comparison sake that would rate 12th this year. Their average for the 22 seasons here is 19,442 per game, which is 5th best this year, though this year they did dip for the Jazz's standards and only averaged 18,680.
Salt Lake City is one of the best NBA markets in terms of attendance by far. Out of all the arenas that sit 19K or more people only Portland and Charlotte have a metro area about the same size as the Jazz do, and only Portland fills their arena up (and Portland also happens to be one of the best NBA markets for attendance).
Come to think of it, has an NBA team ever moved that has had such long term support? The Sonics are the closest I can think of but they played in a very small outdated arena and even then would only get 90% capacity in their later years. The Jazz's worst year at ESA was in line for the average year in terms of capacity for the Sonics in the 2000s.