The fantasy fallout
Willy Hernangomez: Hernangomez had asked to be traded out of New York due to a lack of opportunity. He was an All-Rookie selection last season, but this season had lost most of his playing time to Enes Kanter and Kyle O'Quinn. The injury to Kristaps Porzingis may have opened up some time for Hernangomez in New York, but it seems that the bridge was already burned.
In Charlotte, he will be stuck behind Dwight Howard, and the Hornets have several other contributing bigs, but they also have lacked consistent production from the second big-man slot, so it's possible Hernangomez could get more run. It's almost impossible for him to get less run than he had been in New York, so any extra minutes for him will constitute a win.
Hernangomez is a player I'd put on my watch list, because he showed last season that he can produce when given minutes, but the path to those minutes isn't clear, so I wouldn't run out and pick him up unless another trade or something big changes.
Kyle O'Quinn: With Porzingis down, it was possible that the Knicks would go in for a youth movement in which Hernangomez could have taken more of his minutes. Now, that temptation is gone and O'Quinn likely sees a larger role for the Knicks than he did when Porzingis was healthy.
O'Quinn is less intriguing, because his game doesn't generate big numbers even when he's given minutes. He might get on the radar for deeper roto leagues, where big-man-specific categories could be important, but even still, he's a wait-and-see player rather than one you need to pick up now.
There aren't really any, in this deal. O'Bryant is a net neutral, in that he wasn't likely to get playing time for either team. The Knicks are losing out on Hernangomez's talent, but must feel that the two future picks will help them build moving forward. This was a small deal without huge fantasy ramifications, and for the most part those ramifications are generally positive.