It'll hurt the NBA once this current TV deal is over. Yes, casual fans will watch a lot of "superstar matchups" on national TV, but the NBA doesn't make anywhere close to the money off of them as the do die-hard fans. Losing one die-hard fan is like losing ten casual fans, because the casual fan will sit at home and watch a couple game a week on TV (to see Westbrook play against Lonzo and the Warriors play against the Rockets, etc.), while the average die-hard fan will pay hundreds of dollars a year on tickets, pay $70-$100 on a jersey, pay $200 for NBA League Pass, as well as watch some nationally televised games. While the NBA makes more money off of bigger markets, they're less important, as those markets have more casual fans that will never lose interest in the NBA. The NBA is making the mistake of catering to these markets when these markets (New York, Los Angeles, Miami, etc.) have the least potential to cause a decline in the average annual income of the NBA. Fans of these teams won't get tired of catering to superstars, greedy advertising, specified over-coverage of a few different players/teams. Yes, there's die-hard fans in big markets, but they won't have a problem with the NBA covering their team less, or anything the NBA may do.
The one's who are going to have a problem is Bucks fans, Blazer fans, Utah fans, etc. I'm starting to see die-hard fans get frustrated with the direction the NBA is going, and I think that they'll slowly stop spending a ton of money on tickets, and jerseys (even though ad patches won't be on fan-bought jerseys, I think they'll affect sales), and other factors. The NBA will lose a ton of money as it's die-hard fans get tired of supporting a product that doesn't cater to them, that doesn't care about them, and that doesn't have the parity to give them hope in their team competing in a championship (because the answer to superteams is to form more superteams in big markets, which the media perpetrates, such as "Lebron and PG13 going to LA to play with Lonzo").
The next TV deal will be lower because the NBA will lose more fans in total, but that won't be the biggest hit. The NBA will have to rely even more on the TV deal than before, but I think the media is already regretting the TV deals they've struck with the NBA. The next TV deal will be lower, and with the parity problem combined with the way the NBA is being marketed, there will be less die-hard fans willing to spend a ton of money on the NBA, and the NBA's salary cap will go down. There's a reason there wasn't a big bump in the salary cap this year that was thought to have happen a year ago. The salary cap will drop in a few years, and then the NBA will realize that their marketing plan doesn't work, and they'll have to fix the parity problem. They'll also realize that they need to alter it's playoff system, as playing 82 games for a seed between 1 and 8 waters down each game. The comparison I'll use is the MLB, which plays 162 games, and playoff spots often come down to a game or two. The big difference is, winning your division is meaningful, as you don't have to play a Wild Card game. If you don't win the division, you're battling just to make the playoffs, with the 4th or 5th spot being the difference in home-field advantage in a win-or-go-home 1 game playoff.
If the NBA had parity and cared about the collective product put together by all 30 of it's teams (the way baseball does), I'd pay $200 for NBA League Pass, and I'd watch a lot of other games on National TV.
@HCP will respond with "But it's great players playing great basketball, why wouldn't you want to watch?". My response to that is that the NBA has made me have an aversion to other superstars beceause they overmarket them, and care more about the casual fan paying attention to a select group of stars than they do about the die-hard fans in small markets that supply them with more income. So why would I want to watch Westbrook play because he's great, when the NBA values the fan from Kentucky who's an "OKC" fan just because he geeks out over the collection of stats that is a triple double more than me, a guy who pays for tickets all the time hoping his "small" hometown team will overcome the big-market bias created my the NBA and who gives the NBA more of my money than the casual fan from Kentucky?
The NBA is broken. They're success is hitting a peak right now because social media has created a huge amount of casual fans and the die-hard fans from small markets aren't yet fed up with the NBAs bullshit. However, it's starting to turn, and the NBA is going to realize just how important die-hard fans from small markets are.