According to ESPN, it is estimated that the league bubble could contain 1,500-2,000 people. However, experts have pointed out a lot of weak points in the NBA-Disney plan which could potentially lead to a large NBA cluster infection. Nevertheless, the league is already aware of the risks and are consulting dozens of experts to mitigate the problem.
The obvious weak point is the interaction between the NBA participants and the Disney employees. While NBA participants are quarantined, according to Sandro Galea, Dean of the Boston University School of Public Health, the Disney staff are not. It creates a really complicated situation.
Abraar Karan, a physician from the Harvard Medical School, also pointed out that tests aren't perfect. Unless the NBA invests in daily testing to ensure consistent results, the league's comprehensive plan is a high-risk endeavour.