It has nothing to do with their investment. It was because nbas market share in China is huge. I think you are upset with the NBA here, they chose profits over geopolitics.

What's the leverage?

Naively I would assume that the worst would be that when such a small investor sells his shares then everybody else has an opportunity to make a cheap offer.

What investment is being referred to here for the NBA? The NBA including individual players all defended China. Money being the reason.