Of course no one noticed.
The NBA's a black league and besides the NFL loser Colin Kaepernick, the NBA's been the biggest bastion of BLM-style cheerleading. And the MSM? You think this might have been news before the season's 13th game? Nah. MSM types hate the patriotic anthem just as much as Antifa and Black Lives Matter terrorists.
At Bro Bible, "Mark Cuban Ordered the Mavs to Stop Playing the National Anthem This Season and No One Noticed Until After the Team’s 13th Home Game."
Naturally, this Sky News video (from Australia!) was the only one that came up on a YouTube search, probably not because YouTube's censoring any outlets --- there just are no American outlets that are interested in reporting the story. For shame.