I think a few reasons.
-PR nightmare to just fire him without saying ANY reason. Suspending him, having vague leaks coming out and then firing him would be easier from a PR point of view
-Have no idea how is contract is setup but they could be cheaping out on how much they would have to pay him. I doubt Udoka wants to leave money on the table if he knows he's not going to coach again.
IF HE SEXUALLY HARRASSED
SOMEONE HE CAN BE FIRED WITHOUT PAY.
THEY ALSO WOULDNT BE KEEPING
EVERYONE IN THE DARK
AS TO WHAT TOOK PLACE
IF HE SEXUALLY HARRASSED SOMEONE.
THAT WOULD BASICALLY BE
PROTECTING A SEXUAL HARRASSER.