The Knicks were a public mess for the entire NBA world to see for the entirety of last season. Between Carmelo Anthony and Phil Jackson publicly having a contest to see who could be the most petty, to James Dolan having Charles Oakley arrested, New York was not a happy place to be. So much so that Kristaps Porzingis skipped exit meetings out of embarrassment. He couldn't stand to be around the Knicks' dysfunctional mess any longer.
After word got out that Porzingis was unhappy in New York, executives across the league called New York to gauge trade interest. Any moves that New York might want to make probably won't come until the NBA draft, but that's never stopped executives from trying to get their pitch in first.
There isn't any word whether trade talks actually escalated, but Porzingis still hasn't spoken to the Knicks since he prematurely left. He's clearly not happy with the Knicks and he might welcome a trade at this point. Of course, New York would have to be insane to trade the best young prospect they've had in a decade.
However, if New York saw that there was no chance at fixing a relationship with Porzingis then the return they would get on him in a trade would be massive. He's still on his rookie contract, immensely talented, and almost every team in the league would have interest. A high market means a great return.