So, Imho It's very unlikely that KD will be traded in the summer league.
Agree with that, KD will remain as Nets, unless he will ask for a trade and would not play until he gets traded. Irving will likely get traded as that has been his trademark already, and in the first season he will show up, the next season he will struggle, the kind of superstar he is.
I can see why the Nets would both want to trade him immediately and to wait. If they wait, it gives them more time to try and find the best deal. It also gives them less time with their new players to fit into their team. With Ben Simmons already new, and their 2 stars likely leaving, you'd think they would want all the time they could get to figure out how they're going to make the new roster work. I think bluffing that they'll keep KD and Kyrie might land them a better deal and that's why they're waiting. It could also backfire pretty big.