The Knicks swap KAT with Giannis with the intention of playing him at the 5. This shores up their defense, and the space they have on the floor otherwise is a great environment for Giannis to get his buckets in. Makes use of the massive KAT contract that they put their resources into without having to move any other core pieces. Not too much to explain about why this is good; defense fixed, offense maybe better than it is right now, title window reopened. The young players don't get minutes at the moment but they are capable young players, their minutes are more of a Tom Thibodeau issue.

Milwaukee gets two of their pick swaps back from New Orleans so they can trade everything and begin to tank immediately next season. They also get Zion, who does not fit that plan as a member of the team, but they will be in a much better position than New Orleans currently is to trade him. While Zion definitely is not a great asset, he's much easier to trade for iffy players with big contracts from contenders that have limited options than for quality players that a team like New Orleans would be looking for. They can take on bad contracts to get more picks for him, which will help them tank more and increase their draft capital. Most teams do not have the picks and necessary contracts to get a Giannis trade outright, so splitting it between New Orleans, New York, and the hypothetical team trading for Zion makes it easier to get done. They also get a few young players that have potential to develop into quality players, giving them a starting point for a rebuild. Both teams could maybe throw more picks their way, but this is the centerpiece of what I'd say they would hope for.

Finally, New Orleans gets KAT, a much more available and proven player than Zion, who is still young enough to contend with for years. The team around KAT would still be a defensive juggernaut, which can cover up his defensive shortcomings, and he would likely be at the 4 with Missi playing the 5, minimizing the effect of his lack of rim protection. They're also a very strong shooting team who can give KAT plenty of space to attack the basket, as they've already proven to be able to do for Zion. They can finally rely on their star, and wouldn't have to give up too much draft capital for what is realistically a major improvement in their ability to contend consistently, without having to keep holding out hope for Zion. It's a much better return than they could hope for in most other scenarios.