The point of the anecdote is that the null hypothesis -- that 5-star generals are there basically because somebody "wins" each battle and that a fixed percentage of these will win 5 in a row -- is difficult to distinguish from genuine tactical skill.

That's the point of the article too. We too often attribute to skill what can just as reasonably be luck. Partly because of survivor bias: Zuckerberg et al are the one group out of the hundreds of contenders who succeeded in getting runaway network effects. But if contenders had non-zero chances of success, somebody was bound to succeed. The null hypothesis is that Zuckerberg was just lucky and it is basically not easy to disprove, given that as I said above there's nothing particularly unusual about him or Facebook going into the fight.