Unlike the Meyers Leonard thing which occurred on a stream with hundreds of people listening, KD vs Rapaport seems to be a private conversation and both of them were getting stuck into each other and one of the parties chose to make it public. No different to if they had called each other and abused each other verbally. Not sure if the NBA is now penalizing people for private convos or if they should. Though I guess with text-based online communication conversations that were intended to be private can easily become public if one of the participants so chooses and KD should have realized that.
That said, it's certainly not a good look for KD in the sphere of public influence. It's an insight into his character. Probably not something his sponsors want to see, that their guy is a racist, misogynist, homophobic pig and that's probably where the real punishment, if any, will be mandated. I'm not sure if KD is too big to be cancelled, but there will probably be some moves on that front.