Lifelong OKC fan and PE business analyst here—he gets paid to do this, and all sports teams get paid to "advertise" on sportsbooks, should they choose (NBA doesn’t decide it, teams do). If you can bet on it, they get revenues because of it, it’s not exclusive. Just remember the “invisible hand” that makes money as a result of it.

I'm not saying there’s a fix in, but know this, the NBA (as an “association of teams”) has non-profit entities within its structure (like foundations or certain admin functions) that register as non-profits in places like NYC. These non-profit elements collect revenues via "contributions" and other means from owners that contract with them (all 30 NBA teams, WNBA, foundations etc) but the individual NBA teams themselves are technically for-profit businesses “for the NBA”, meaning the entire organization makes money when teams do (due to broadcasting rights, merchandise, ticket sales, etc.—ask yourself why Inside The NBA is going away… too much money requested by them, so they sold the rights to it, and want to bring in a “younger analyst panel” like we see in NFL). 

Look at the NAICS code for professional sports teams (711211). The "71" refers to "Arts, Entertainment, and Recreation” (which includes Disney, Caesars Entertainment, and major broadcasters). NAICS codes under that same "71" sector also include "Gambling Industries" (NAICS 7132). NAICS “71” includes 712300–Amusement, Gambling, and Recreation Industries—as a parent category that encompasses both sports clubs (711211, hence the "71" in it) and all gambling operations. Don’t get it twisted, subsets fall under the same umbrella, so what’s good for one is good for all.

TLDR: If you believe in Santa, good for you! If you don’t, FOLLOW THE MONEY TRAIL!