Moscovitz did not say that employee #100 made $200M at FB. Read the article. First, this was an overly simplistic analysis. It assumes a strike price of $0.00... Which never happens, and certainly wouldn't have happened by the time FB hit 100 employees. It assumes full vesting. It assumes no lockup on liquidity. It assumes no dilution from exiting... which, in the real world, never happens.
You can actually see how much money FB's top shareholders were worth at their IPO. Very, very few employees made over $10M. TEN. Before tax.
A lot of people front in SF / the Bay Area. Very, very few are worth over $30M in liquid net worth.