Warren Buffett waited until the very last page of his annual shareholder letter to reveal a big change: Shareholders will be hearing more from top lieutenants Ajit Jain and Greg Abel. The pair, seen as the top contenders to eventually replace Berkshire Hathaway’s 89-year-old chief executive officer, have often remained behind the scenes, tending to Buffett’s collection of insurers and its array of businesses that span from energy companies to the Dairy Queen fast-food chain. But a quirk of last year’s annual Berkshire meeting, during which Jain and Abel both answered some shareholder questions, will become more formalised at the