I don't think the Jazz necessarily want to trade Rudy, but there are a few things to consider here:
1) Rudy is a FA at the end of next season and could walk like Hayward did.
2) Rudy's trade value is never going to be higher, given that he's an All Star and 2x DPOY in his prime.
3) The Jazz are willing to pay Gobert, but I doubt they want to pay him a supermax. This could make his case similar to Demarcus Cousins and Kemba Walker, both of whom were traded.
4) Look at the haul that New Orleans got for Anthony Davis last year, even after AD chilled his trade market by saying he'd only re-sign with the Lakers.
5) Mitchell and Gobert don't fit together as well as, say, Gobert and Hayward did.
6) The time window for contention that the Jazz planned for with Rudy may be getting interfered with by the coronavirus. Eh, not sure about that one.
I think it would take a pretty massive trade offer for the Jazz to move Gobert, but I don't think it's impossible. If Chicago offered Markkanen, Carter, a lottery pick this year and a future pick, the Jazz might be tempted. It would have to be a homerun deal for the Jazz.