Yeah that's why I think time will tell. I would think that a predefined outcome isn't what drives ratings long-term. Warriors going 16-0 is a story this year, but would already be boring the next one. The only data I have here is soccer, where the richest league (EPL - England) definitely is not the best in Europa but by far features the most competition.
Germany, Spain and even Italy feature better teams, but revenue-wise can't touch the Premier League.
I wouldn't like a "super-team" league, but I would probably still watch if that's what millennials want. I think though that the NBA will eventually introduce rules to prevent this.