Why They Do This
Orlando
They clearly don't have Bamba as a part of their vision moving forward.
They need guards desperately due to how many injuries they have.
Since they are trading away one of the better prospects(projects) in the league, LA needs to make a move to send a pick to Orlando
L.A.
Rumors are swirling about adding defensive depth at center. Bamba is probably the best plug and play guy for this. He can't be consistent on offense yet, but when you have a 7'10" wingspan, you'll block/deter a lot of shots in your minutes. Not to mention L.A. has LeBron who can pick up the scoring if need be.
OKC
They add a low risk/high ceiling player in exchange for one of their better picks. They also have a high chance of re-signing Cook after the season, and in a thin draft where they'll still have 2 first rounders, this is probably more valuable for most teams anyways.