He would most likely make a nice addition.
I just see no way that if the Knicks made him available that the Celtics would best other teams trade proposals. And, I think the Knicks love the guy for what he brings for what he makes and won't be trading him.
The other thing we have to remember about trading for Randle, we might not be able to use the TPE on him as and might need to salary match, maybe even send out more than Randle's salary, because, I believe the Knicks are really close to the minimum team salary number.
For instance, a Nesmith, Grant, TPE and picks trade might not work since the loss of salary would put NY well below the minimum team salary number.
Maybe you make it a three way with Oubre going to NY with a GSW pick(s). NY stays above the min salary line, get 2 prospects and picks from Boston, pick(s) for taking on Oubre, GSW gets luxury tax relief, Boston gets Randle.