I'm fine with them boycotting the game to draw attention to the issue. I'm just not sure if boycotting a game is the best way to make an impact. You boycott a game, the media writes about it for a week, then everyone moves on. How does that effect real, lasting change? You think the police or the attorney general of Wisconsin will care that some rich basketball players boycotted a game?
These players are in a better position than most of us to try and effect meaningful, lasting change because they are rich, and money is how you effect change in our world. Donate to organizations that advocate for the cause of racial equality. Get into politics. Use your fortunes the way that George Soros has used his for the Democrats, and the Koch brothers have for the Republicans. Create political action committees and fund them to get more black candidates to run for political office at all levels of government, and to push for police reform. Set up foundations to influence public thinking. Bankroll the organization of rallies to keep attention focused on police reform and racial justice.
That's how you affect real change. Not by boycotting a game. And they are in a better position than most of us to do it, because of their fortunes. Certainly boycotting a game will draw attention to it, just as Kap's kneeling - and Trump's vitriolic response to it - drew attention to police brutality in the first place. But to effect real change you need to spend money. If each of them donated say 10%...how much money would that be? And what could be possible by spending that money? Just my 2c.