Selling off shares from insiders is a publicly announced process that involves coordination with the SEC in advance, so "pump and dump" doesn't really apply here. That terminology usually applies to penny stocks that are traded on minor exchanges, where a price increase of mere pennies could represent a very high percentage increase, making manipulating the stock price through fraudulent claims potentially very profitable for the manipulators.

He could sell shares early but that news would also probably very negatively affect the value of the shares he's selling. Not really great when the CEO is not confident of the long term value of his own company's stock.