Earlier quoted context omitted.
Anomalies aren't necessarily evidence but in this case, and in many important general cases anomalies can be critically important evidence. He and his career constitute evidence that "height" is not a requirement to be an elite basketball player. It's definitional and not arguable. In science today's "anomaly" is sometimes the evidence that leads to tomorrow's breakthrough.
It's not a requirement but there's a massive correlation between the two. It's just like when people say they shouldn't worry about monetizing because of Google.
Most tall people suck at basketball. Some elite basketball players are short. The fact that most elite basketball players are tall does not really help us write our basketball-success-prediction algorithm. People dedicate their careers to solving this problem. It is very hard.
Since this is hard and likely to yield garbage results anyway, and most likely only leads to worry, time-wasting and excuse-making don't bother with these thoughts. Instead, erase every doubt from your mind, get in the long boat, row west and find Valhalla. (Given Google somehow came up I had no choice but to bring Valhalla into the discussion.)