You make a very good case that it could be bad for the NBA in the long-term if the Warriors keep dominating. When you take out the "anyone could win" aspect of the game, people who aren't fans of the winning team tend to lose interest. Fewer eyeballs on screens and fewer butts in seats means less money.
I'm not surprised that Silver hasn't addressed it yet, but if the domination continues, I would expect they take action, be it changing the cap structure to make it more difficult to get multiple stars together... or it could be changing the draft to align more with the NFL's format which is to have the order be assigned by how the team ranked the previous year. Either way, you know they're not just going to let the money slip out the door because fans aren't getting a compelling story line.