Amid a feared takeover bid from Tesla CEO Elon Musk, Twitter’s board of directors threatened to fight back with a “poison pill” strategy, allowing it to flood the market with new shares if Musk buys more than 15 percent of the company. Fending off Musk’s $43 billion offer by creating more shares could dilute the value of shareholders’ stock — but Twitter’s 10 board members own just a tiny portion, Musk noted in an April 16 tweet: “The Twitter board collectively owns almost no shares! Objectively, their economic interests are simply not aligned with shareholders.” That same day, even Twitter...