Why, isn't the max the Jazz can offer more than what other teams can offer? I get the Jazz may want to extend him and get the extra fifth year, but letting the market set his value doesn't make them pay any more if he's going to get the Max regardless. This isn't Hayward who would have extended for 12 per then ended up getting max.
Edit: For the record, I have only been able to see a few games, so I haven't been able to see the impact that he has had. I'm just saying that hypothetically if he is going to get the max either way there is no harm for the Jazz to wait, financially, but they may want to do it to show good faith in him.