I know see the significance of audio / visual evidence. Sterling's audio recording is damning because it is out there for everyone to access and never be forgotten. Years from now people can hear for themselves how racist Sterling is. Even though Sarver was found to have said racist and misogynistic comments, without audio for people to get first hand perspective for themselves its easy to downplay because its coming second hand.
That is the only difference I can see from Sterling to Sarver but Sarver is worse in that he is both racist and sexist. I believe Suns players, Monty and Jones won't cause a stink because they've personally never seen that side of Sarver and he always appears to be supportive of his players and looks diverse in his hiring of Monty and Jones. But to me, this is his get our of jail card. He can say I and do what I want as long as I appear to be a supporter of diversity and just play it off as just being a "fun" owner.
The NBA's not taking a firmer stand will only encourage owner's to operate above the law, not just in NBA but also in other leagues as well. Look at Dan Snyder who allegedly cooked books in order to get more revenue share from the NFL screwing over fellow owners. It appears that has been swept under the rug as there hasn't been a peep about it since it was reported a few months ago.