The fact no one offered Tristan a contract this year is pretty much immaterial. He was a RFA and it was widely assumed the Cavs would match any offer.
Haynes and Windhorst are both reporting that multiple teams would offer Tristan the max next summer, and I see no absolutely reason to disbelieve them. I mean, I don't even think it's a matter of debate.
People are made at Rich Paul and Thompson, but if they know Tristan will command the higher max next summer, why shouldn't they use that as leverage? Why should they sign for 5/$80M when by waiting a year they can get 4/$100M+?
As Windhorst says, this is a simple matter of limited supply and huge demand next summer. Under the best of circumstances, the CBA distorts players' salaries, and this distortion is just compounded by a cap going up $20M in one year. I mean, we all knew this was going to happen when the players' association rejected the idea of cap smoothing.
Comparing Tristan's situation to Draymond Green's (not saying anyone has recently, but he is the natural comp) also has problems. I couldn't understand why Green signed that below-market contract when he did, given that I don't doubt that literally half the league will be more than willing to pay him the 2016 max. I guess either the money didn't mean enough for him to prolong the negotiations or he got bad advice from his agent.