Wrong, if one is concerned with restricted shares then sure they would use the OS. But why stop there, you would have to calculate the fully dilutive effect of all dividends and preffered.
While it primarily affects company ownership, dilution also reduces the stock's EPS (net income divided by the "float") which often depresses stock prices. For this reason, many public companies calculate both EPS and diluted EPS, which is essentially a "what-if-scenario". Diluted EPS assumes that potentially dilutive securities have already been converted to outstanding shares thereby increasing the denominator (the "float").